GameGoo - Learning that Sticks!
Earobics sells software and training materials for teaching reading. Some of our local special education reading programs are using the earobics material. I can't speak for the research behind it; there's very little funding for research in this area and well designed intervention trials are very, very expensive.
Here they're offering free "Flash" based phonetic and reading oriented games. Because they use Macromedia Flash they run very well on both Mac and PC. They don't demand a lot of processor power. Quite impressive!