I forgot I had Alchemy, went back to it and played around again. The lower 2 sketches are a month or two old; the top one is from tonight.
Also diggin' on CS5's new brushes. They may not offer the sophistication that users of Painter are used to, but I find them rather novel and enjoyable. Can't control them properly, though, so I just use them for making messy stuff like grass and clumpy trees.