It was through BitInstant, it is also possible to do it through bitcoin-otc.com , though it's a real PITA. You might be able to find someone on the forums, though that involves trust. I imagine you are trying to arbiter the 5-10% diff?
Yes, I have a few BTC just sitting in my wallet. Would like to try to do something with them regardless how small arbitrage with this amount may be.
Thx for you advice.