My mom had around $300 of half dollars(I have no clue why) and I asked to look through them all to see if any were silvers. I was only looking for 64 and below, but i found this really shiny 2008 one and wondered if it were worth anything. I also wanted to know what to look(years, mints) for in Quarters, dimes, and halves as i probably missed some silvers possibly... Here it is... Front: Back:
With half dollars, you want to look for 1965-1970 as well, since those are 40% silver. You may want to give them another look. The coin you found is a beat up 2008S clad (unless the edge is pure silver) proof. It's not really worth anything more than 50 cents in that condition (although I keep all the proofs I find regarless of condition) As for what you should look for, check the FAQ here: http://www.cointalk.com/t202337/
Looks like I'll be looking through all the halfs again. Next time I'm going to try dimes? Not sureee.. Thanks for the info!