[dba-Tech] Oh God one bad keystroke!

The wrong thing was selected and I just toasted lots and lots of work. I
thought I was deleting selected files and failed to notice that the selector
was on a directory, and Windows said "Too big for recycle bin" and I said
ok.
I know that deleting a file merely changes one byte in its header. How can I
reveal them and get them back?
I'm stupid, I'm stupid, I'm stupid. But I don't want to throw away the last
couple of days' productive work. 
Help!
TIA,
Arthur