iLike (service)
With a plug-in for Windows Media Player or iTunes, iLike installs a sidebar displaying artist news (recent albums, local concerts, and so on) based on music already residing in your library. It also recommends new music that you might like, offering song samples. You can share playlists and preferences with other iTunes-using friends, too.

Slacker (service)
Start with your pick of Internet radio stations in Slacker's in-browser player--from 90s Alternative to Outlaw Country to Big Band/Swing--or type in the name of a band to get a station covering that sort of music. Afterward, you can customize the station with your choice of artists, and fine-tune options such as song popularity and age. You can also download a stand-alone software player.

Lala.com (service)
If you take the time to upload all or part of your MP3 collection to Lala.com, you can then play those songs anywhere through a Web browser. Though you can't download the songs to another PC, you can use a downloadable applet to sync your Lala music (both uploads and music purchased from Lala) to your iPod.

Wavosaur (download)
When you need to edit short audio programs, sound effects, or loops, give the free Wavosaur audio editor a try. It has all the basic audio editing functions (cut, copy, paste, crop, fade in, fade out, and so on), and some audio analysis features, as well. You can use it to record sound and do batch-processing on a folder full of files.

Desktop dustomization

WinMatrix (service)
This customization clearinghouse serves up a dizzying array of guides, links, and posts for the serious tweaker who wants to change the look and feel of Windows XP or Vista. If you're new to the XP customization game, start with the site's excellent beginner's guide.

WindowBlinds (download)
For "skinning" the various Windows interfaces, Stardock's WindowBlinds theme manager is the tool to use. After you pick up the program, head to Wincustomize.com for a kid-in-the-candy-shop feeling as you browse through 522 pages of free and for-pay skins that beautify the taskbar, window borders, Start menu, and other elements. The free trial won't skin Internet Explorer and has a few other limitations; the full version runs $20.

Wincustomize (service)
Here you'll find a wealth of free wallpaper and screen savers, as well as themes and packages, for Stardock's excellent Windows customization programs. You can nab 50MB of downloads right away, or register (at no cost) and bump that up to 500MB.

SlickRun (download)
If you're a Windows power user who constantly heads to the Run command in the Start menu, SlickRun can save you some time with its floating on-screen command window. You can also create "MagicWords," one-word aliases that quickly launch programs when you type them into the command window.

Vista Start Menu (download)
Despite the name, this beefed-up Start menu runs on Windows XP as well as on Microsoft's newer OS. The much-larger menu can make getting to programs easier if you have a bunch installed, and it also provides quick access to autorun programs that are set to start with Windows.

RealWorld Cursor Editor (download)
Replace any of the 15 Windows pointers with this do-it-all app. You can download ready-made pointers or use the built-in editing tool to create new ones, from scratch or based on existing images.