Interestingly enough, those My iTunes widgets that popped up last week have a new distribution partner in the form of Widgetbox. While the widgets you'll find at Widgetbox's site are the identical to the standalone Apple widget builder you get sent to via the iTunes music store, Widgetbox also has their own widget called MixIt that will let you share your iTunes iMix on blogs and Web sites.
If you're unfamiliar with the iMix feature, it lets you publish any regular iTunes playlist to the iTunes music store for others to view, rate, and (hopefully) purchase. A neat idea in theory, but if your music's ID3 tags aren't up to scratch, or the store doesn't have a track, it will simply skip the song entirely. This new widget will take the album art from the songs that have made the jump to your iMix, and give people a simple way to browse through your tracks by album.
The real downer about these new iTunes widgets is that they don't play song previews on their own. Your potential viewers need to have the latest version of iTunes installed just to hear a 30-second preview clip. In comparison, many of the solutions featured in our "Eight (and a half) free Web music players" guide offer full streaming versions of the songs at no cost, and without the need for software.