I did this last year. Got @ $140 bucks. It was money from a corporate common stock buyout that happened over 10 years ago. They (the buyer) had my last address in PA but couldn't find me, so the money was put in the PA Treasury until I came to claim it.
Someone told my dad (still in PA) that they saw my name on a list in the York county newspaper. I made a phone call, filled out a very short form, mailed it and got my money within in a few weeks. Not life changing money, but a nice surprise...