Is there a wallet.dat for OSX? Where is it located?
Bitcoin Wallet on Mac OS X located in ~/Library/Application Support/Bitcoin/wallet.dat
EDIT: Mac OSX Lion came out and it has ~/Library folder hidden, see the answer from chilled35 to access it with Finder.
In order to see hidden folders, such as
From there, you will see all the files associated with your wallet.
Having moved all my BTC to another location, I recovered more than 5 GB of storage space by deleting my local wallet.