My very first perl program: (from a couple years ago)
#!/usr/bin/perl
# first tries at random sigs

@str=split(/\s+/o,`ls sigs/`);
srand;
`rm /nfs/user/l/lillith/.signature`;
`cp /nfs/user/l/lillith/sigs/@str[rand(@str)] /nfs/user/l/lillith/.signature`;
After contemplating this as many, many lines of C++ code, I was happily amazed that I could cut it down to 7 lines.

Of course, then I showed it to a friend who scrunched it down to 4, including the #!/usr/bin/perl.