I did this last summer.
I lucked out big time in that I found a realtor through Google and she was really good - sent e-mails daily (or multiple times/day) with updates/questions/etc, kept me in the loop with everything, and was willing/able to do all the hands-on house stuff as far as making sure that it looked in good shape, was ready for viewings, that repairs had been done, etc.
I was renting my house since I moved here, so my tenant moved out at the start of June 2012. House got listed mid-June, had an offer in early July, and we closed the first week of August.
The major hurdle I had was with the title lawyer/insurance. They'd been given advance notice that this was an international sale and that I couldn't be present physically, yet they still waited until 3 days before the closing date to send me documents and tell me they had to be notarised. I had a panicky few hours until they agreed that a UK notary would be fine, and then I spent a fair chunk of change getting the documents notarised and overnighted to the US. (Which turned out to be a waste as they then moved the closing date back 3 days, and as a bonus didn't tell my realtor so she showed up for a meeting which never happened.)
In those documents I signed a power of attorney for my realtor so that she could sign all the documents for me at closing. It was pretty straight-forward, and just specified that her POA was limited to the transaction on X date with Y house for Z price, etc. (I don't know how much protection it would have been if she'd been tempted to screw me over, but luckily it wasn't an issue!)
About a week after closing, I got a check mailed to my bank in the US with the amount leftover after legal fees, agent commission, etc.
Hope that helps.
