Song requests by mobile phone

Night Life
Some party people are using their mobile phones to influence the music at their favorite nightspots.

Rather than pumping quarters into a jukebox and hoping for the best, or invading a DJ's personal space with requests, partyStrands ( partystrands.com) users send text messages with their suggestions to a TV or projector in the club. The service works with or without a DJ, so you can get your picks straight into the evening's lineup. You may want to have someone keeping an eye out for the potential buzz killers, such as pop requests at hardcore punk party. You can also vote on songs and post pictures and SMS messages on the screen.

PartyStrands is based on a recommender or "discovery" technology called MyStrands. It is the kind of system you will find at many online music and bookstores (think "Listeners also bought" at the iTunes Store), and at Goombah.com, where you can connect with people who share your passion for Air, or Air Supply.

You may be able to save yourself a small fortune in cover charges by using partyStrands to peek inside nightclubs and house parties before adding them to your evening rotation. At mobile.partystrands.com, you can see current playlists and photos of the crowds at clubs using the service. The site displays a list of SMS users at the club, and the text messages they are posting to the communal screen inside.

PartyStrands is bigger in Europe than it is in the United States. MediaStrands Inc., which developed MyStrands and partyStrands, has offices in Corvallis, Ore., and in Spain. The company said that Wonder Bar in Allston is the sole Boston-area venue using partyStrands.

Valentine's Day

Cash for that unwanted rock

Here's a website many of us could have used at some point: at I Do Now I Don't ( idonowidont.com) you can sell the engagement and wedding rings that have outlived "til death do us part" commitments.

The site is aimed not merely at those who are divorced, but those whose engagements and proposals have gone up in flames. Its founder and chief executive, Joshua Opperman, says he got the idea for idonowidont.com after his fiancée dumped him, leaving only her engagement ring behind. (Opperman says the jeweler offered to buy back the rock for a fraction of what he originally paid.)

Since the site's launch about six weeks ago, losers in love (and, no doubt, a few with other motivations) have sold 85 rings, according to I Do. Late last week, there were a mere 90 items up for auction. Only two had received any bids. I can imagine it is hard to build a reputation of trust in the jewelry business. I Do appears to be off to a slow start.

Hitachi records to hard disk or DVD

The more I see of hard disk drive camcorders (and as their prices inch down), the closer I get to ditching my old cam and its cumbersome videocassettes, along with their mysterious contents. HDD camcorders offer nonlinear access, letting you jump around in edit mode to quickly grasp what you've got stored on the internal drive. They also make it easier to grab the camera to shoot those moments that can present themselves suddenly.

Hitachi's DZHS300A ( hitachihybrid.com) is on my shortlist for a new camcorder. Its 8 GB hard disk drive holds three to six hours of video, depending on which recording quality you select. It also records to DVD (up to 60 minutes per side). As with many camcorders, you can capture still images onto an SD memory card.

On the road, when your hard disk fills up, you can back up your material by burning it to a DVD directly, inside the camera. The DZHS300A has some in-camera editing features, and you can download from the camcorder to either a Mac or PC.

The DZHS300A (about $600) has a 25X optical zoom and a 2.7-inch LCD monitor. Hitachi also claims the camera is rugged enough to withstand much of the abuse it will likely get on your family vacations.