Mikael Lind offers free piano improvisations
Swedish-born/Icelandic-living artist Mikael Lind recently recorded a mini-album of piano improvisations and is offering the collection as a free download: http://mikaellind.blogspot.com/2009/06/piano-improvisations-free-mp3-album.html
I haven't had a chance to listen yet myself, but the songs he has streaming in the sidebar sound quite good (though a bit more fleshed-out).