DataRescue II might be able to, if you shut the machine down immediately and did not continue to use it (PLEASE tell us that you are not posting from the same Mac ...) OSX overwrites deleted sectors quite quickly, so your chances go down with every minute you continue to use the machine.
I've spoken to a few people that have had decent results in recovering files with Data Rescue II. It costs $100, and the free version can rescue files that are up to 500kb in size. If ya need it bad enough, you could justify paying for it.. if not, *shrugs
I've once recovered quite a bit of deleted data using File Salvage, it wasn't perfect though and alot of files, especially big ones, were pretty much permanently damaged. Small jpegs usually turned out fine though.