National Geographic's International Photography Contest attracts thousands of entries from photographers of all skill levels around the world every year. While this year's entry deadline has passed, there is still time to view and vote for your favorites in the Viewer's Choice competition. National Geographic was kind enough to let me choose a few of their entries from 2009 for display here on The Big Picture. Collected below are 25 images from the three categories of People, Places and Nature. Captions were written by the individual photographers. (25 photos total)

A kiss - a simple act that can convey a diverse array of meanings. A kiss can be intimate and private, or meant for public display, it can convey love and affection, or simply provide comfort. Its use as a greeting is under fire in our current climate of H1N1 fear, as the French government has begun encouraging citizens to forgo "la bise", their traditional cheek-to-cheek kiss, for health reasons. Gathered here are 33 recent photos of kisses expressing greetings and farewells, congratulations and joy, respect and, above all, love. (33 photos total)

Today, we have three shorter stories, from The Israel-Syria border, Tanzania and Malaysia. Each of these stories caught my eye over the past year, yet I never had enough photographs of each to run them as their own Big Picture entry. Today, I'm happy to share them with you in a single entry in three parts. Below, you will find the story of an Israeli Druze bride who traveled (by foot) north to Syria to wed - and to never return, because Syria and Israel do not have diplomatic ties. You'll also see the faces of a hunted minority in Tanzania, albinos who live in fear of being murdered for their body parts, which will be used for talismans and luck potions. And we end with a visit to a clan of Bajau people, or "sea gypsies", an indigenous group living a seaborne life in boats and huts on stilts, rarely coming ashore, off the coast of Malaysia. (31 photos total)

Combine two of the most common materials found on the surface of our planet - dirt and water - and you get mud, which, in turn, can be played in, struggled through, rubbed on for medicinal value, or just worn for fun. Collected over the past few months from festivals sporting events and more, you'll find here photographs of people around the world playing with, wallowing in, wearing and just dealing with mud - one of the filthiest entries on the Big Picture to date. (31 photos total)

We humans are natural dancers. Dances can be celebrations, or for praise, or for an audience - or just a simple act of letting the rhythm move your body. Dancers can communicate ideas, preserve cultural identities, strengthen social bonds, or just have a lot of fun. Collected here are recent photographs of us, human beings around the world, professional and amateur, in motion for all of the reasons above and more. (39 photos total)

Photographer Jason Hawkes returns to The Big Picture once more, this time venturing away from London (seen previously here and here). Recently, Hawkes has been carrying his Nikon D3 aboard helicopters around the world, hanging out the doorway and capturing landscapes - most somehow affected by humans - below. Today, he has shared with us 26 more of his favorite photos from above France, Las Vegas, Hong Kong, the UK and more - with links to Google maps where available. (26 photos total)

Today is Earth Day, a day set aside for awarenesss and appreciation of the Earth's environment, and our roles within it - this year marking the 40th anniversary of Earth Day. As a way to help appreciate and observe our environment, I've collected 40 images below, each a glimpse into some aspect of the world around us, how it affects and sustains us, and how we affect it. Happy Earth Day everyone. (40 photos total)

Started in Sydney, Australia in 2007, Earth Hour quickly grew into a global observance. More than 1,000 cities in over 80 countries observed Earth Hour 2009 on Saturday March 28th, as homes, office towers and landmarks turned off their lights for an hour starting at 8.30 pm local time to raise awareness about climate change and the threat from rising greenhouse gas emissions. Collected here are a series of before-and-after photographs - which (starting with the second one below) will fade between "on" and "off" when clicked. Let me state that again, since I know not everyone reads the whole intro here - starting with image #2 below, click on the image to see an animated fade between "on" and "off". This effect requires javascript to be enabled. (17 photos total)

When the economy makes big news, many photographs of people at work come across the wires, usually to help illustrate a particular story or event. By collecting these disparate photos over the past few months, I found that a global portrait emerged of we humans producing things. People assembling, generating, and building items small and large, mundane and expensive, trivial and important. I hope you enjoy this look into some people's work lives around the world. (45 photos total)

The Earth Observatory is a website run by NASA's Earth Observing System Project Science Office (EOSPSO). Bringing together imagery from many different satellites and astronaut missions, the website publishes fantastic images with highly detailed descriptions, feature articles and more. Gathered here are some standout photographs from the collections in the Earth Observatory over the past several years. For more images and information, please visit the Earth Observatory site itself. (23 photos total)

2008 has been an eventful year to say the least - it is difficult to sum up the thousands of stories in just a handful of photographs. That said, I will try to do what I've done with other photo narratives here, and tell a story of 2008 in photographs. It's not the story of 2008, it's certainly not all stories, but as a collection it does show a good portion of what life has been like over the past 12 months. This is a multi-entry story, 120 photographs over three days. Look for part 1 and part 2 earlier. (40 photos total)

2008 has been an eventful year to say the least - it is difficult to sum up the thousands of stories in just a handful of photographs. That said, I will try to do what I've done with other photo narratives here, and tell a story of 2008 in photographs. It's not the story of 2008, it's certainly not all stories, but as a collection it does show a good portion of what life has been like over the past 12 months. This is a multi-entry story, 120 photographs over three days. Look for part 1 from yesterday and part 3 tomorrow. (40 photos total)

2008 has been an eventful year to say the least - it is difficult to sum up the thousands of stories in just a handful of photographs. That said, I will try to do what I've done with other photo narratives here, and tell a story of 2008 in photographs. It's not the story of 2008, it's certainly not all stories, but as a collection it does show a good portion of what life has been like over the past 12 months. This is a multi-entry story, 120 photographs over three days. Watch for part 2 and part 3 tomorrow and the next day. (40 photos total)

Hurricane Ike just rolled across Cuba, and soaked parts of Haiti - both regions still reeling from recent Hurricane Gustav. Ike appears to be weakening now, but is headed tward the Gulf Coast of the U.S., and may yet strengthen. The crew aboard the International Space Station was able to take a photo of Ike from 220 miles overhead last Thursday - one in a long series of great NASA photographs of hurricanes from space. Here are some of the best, from the past several years. (25 photos total)

The Space Shuttle Discovery successfully launched last week, becoming the 154th manned US space mission. It flew to the International Space Station, delivering (among other things) a Japanese module called Kibo, repair parts for a broken toilet, a Buzz Lightyear action figure, one of Lance Armstrong's yellow jerseys, and 18 sesame seed bagels - the first bagels ever to reach Earth orbit. Completion of this mission will leave only eight flights remaining in the Space Shuttle program until its end in 2010.

One of the best features of the space program has always been astronaut photography, and I will take this opportunity to share some of the best photographs of Earth's skies, taken from above - way above (over 200 miles to be more exact). (15 photos total)