I've been running my local bitcoind with the getblockbycount patch just fine. The patch has to be somewhat manually applied because there are conflicts since the last time that branch was rebased or merged. Someone should either update that branch or put an updated version somewhere else. Or even better, get the patch merged into bitcoin.

psy: In what experience I had, the biggest barrier is doing the initial load of the blockchain. It was fairly I/O intensive and wrought havoc with my VPS. I eventually had to give up (as it would have taken several days to finish), and run it instead on my local machine. However, the particular host machine my VPS is on has had a history of high I/O load from other users, so it's possible it might work better elsewhere.