You have your Twitter. And your Facebook. And your Flickr. And your MySpace. And, if you're like most people, the list of Web sites you use to share information with your friends, family, and the world at large probably goes on, too. But updating all of those sites doesn't require logging in and out of several different services, thanks to CellSpin. When it works, this application offers a really handy way to send audio, video, pictures, and text updates to a variety of sites right from your mobile phone.

CellSpin's mobile software works with a variety of cell phones, including the iPhone, many BlackBerry models, several Palm phones (both Palm OS and Windows Mobile-based models), and various other handsets. For a complete list of compatible phones, visit CellSpin's Web site. (If your phone is not compatible with CellSpin's mobile software, the company offers a workaround: You can update your sites by sending content via SMS, MMS, or e-mail.)

You create an account online and CellSpin sends a link to the software via text message. (If you're using an iPhone, you can download the app directly from the App Store.) You decide which sites you'd like to use CellSpin to update; the list of available sites includes eBay, Facebook, Flickr, Google Blogger, LiveJournal, LiveSpaces, MySpace, Picasa Web Albums, Pownce, Twitter, TypePad, Wordpress, and YouTube. You'll need to enter your username and password for each site so that CellSpin can send information directly to these sites. (Some of this account management can be done directly from your phone, too.)

Now you're in business. From your mobile phone, you can capture photos, voice notes, video clips, and create text notes, and send those directly for posting to you favorite sites. You also can send content that already exists on your phone right to those sites, too. And when you choose or create something that you'd like to upload, you can decide how many sites you'd like to send it to. You can, for example, send a photo to Facebook, Twitter, and Flickr simultaneously. This is what gives CellSpin an advantage: It eliminates the need to log in to multiple sites.

My only complaint about CellSpin was that it didn't always work consistently. I tested it on a first-generation iPhone, and sent photos to several Web sites. Most of them worked fine, but I occasionally had problems getting photos to show up on Facebook. CellSpin asked me to re-authenticate my account (by re-entering my password) and then said the photos had been posted. But in a couple of cases, they never showed up on my page. Still, the application is free, so you can't complain about the price.