K10D Remote
Well, I didn't actually buy mine, it was given to me by the Rep. But they are available quite a few places on-line, as well as some after market versions. Here is the link to the Pentax site where it shows Pentax's OEM version:
Pentax Remote F. If you buy the actual Pentax remote it has a place in the K10D's optional battery grip to store it when not in use. I did have one of the after market versions at one time but it didn't work as well and went through batteries like crazy, it was one day while I was trying to get the after-market one to work that the Pentax rep handed me a brand new original one and said "It's yours, now throw that other one away".