A number of years back I took it upon myself to check the Unclaimed Funds site for myself, relatives and friends. Never found anything for me but did have a bit of luck for others.
Usually it was small amounts from utility deposits, interest checks, etc. Most I ever found for someone was $1,200. The info is always being updated so even if you didn't find anything a few years ago there might be something now. Case being that I got an email today from someone I had shared the link with 3 years ago and some cash showed up for them.
Probably the greatest story I got was from a woman I knew in Minn. I gave her the link and though she didn't find anything for herself she did find that her former Father-in-law had over $30,000 held by the state. She knew he had died a few years prior to her finding this.
Now her former husband was 2 years behind in child support and alimony. She figured he was sitting on this until he felt safe to go after it. She got ahold of a lawyer and he petitioned the court. End result was she got a good chunk of that cash. So ya never know.
http://www.missingmoney.com/Main/Index.cfm