Yep, the "end of the accessories line" is coming for the K10D and K20D now that the K-7 and BG4 grip are here. Get them while they last at $30 USD:
Kirk Enterprises : Camera Plate for K10D with/ D-BG2 battery grip
Oddly enough, the "K20D plate" for the body without the grip is still $55...
BTW, these are Arca-Swiss compatible quick-release plates. If you don't know what that means, you don't really need one. Kirk makes really good stuff!