Here's my soundcloud page

You can upload in any format and if you make the tracks downloadable, they will download in the format you used for uploading. Very useful for sharing and I used it to offer tracks for the Blue Plate CD.

Most of mine are in flac format except for one (Westmorland) which is an mp3. Playback online using the soundcloud player is mp3.

I like the fact that they give you playback time rather than disk space for your tracks. The free account gives you 2hrs which is two CDs worth and is much more generous than MySpace.