Yes, and I even find it useful.
Take the cash (the owner clearly doesn't need it) and destroy the wallet (so that no bad hands get on those credit cards)
Call one of the credit companies to let them know the wallet has been found (with $200 cash in it)
Think well, the guy clearly doesn't need the cash, and it probably wouldn't hurt his net worth much if you went shopping with the credit cards
Go and tell the Bill Gates foundation so they act on it immediately. It is for public good after all.
Do nothing and wait for your friend to act on it himself, even though spreading the word would help a lot of people faster.
Go act on it yourself. Your friend can thank you later for the piece of the pie that you'll share with him.