I had two K10d's for a time....great cameras. i look back on images shot with them and still am impressed. I ended up selling both a few years ago, but I did get $300+ for each so I think it made it worth it. However a part of me wishes I still had them for sentimental value.
I'd say if there is someone in your life that has an interest in photography and wants to learn on a DSLR you donate/loan it to them....knowing that if they stick with photography they will get bitten by the gear bug at some point, want to upgrade, and then you get your beloved K10 back