Thats some fine golfing... I might have to join the mailing list. ;-) The only one I could improve upon was number 5:

#!/usr/bin/perl -n
}{printf"%010d\n",$.
[download]

Which is one char shorter if you don't count the command line opt...

Update: The rules for this particular course counted the command line opts, so I'd take a three stroke penalty for ' -n' which puts me two strokes behind on the leader board...

-Blake