I love what you can do with sed, but I'm not looking for "braintraining"
Got enough thinking to do without decoding sed one liners
(Or do you cheat and use the manpage
Its amazing what tools the command line hides, until you find them. I found sed years ago after hunting for some way to have grep output lines from a starting line match to an ending line match. sed can do that so easily... (as: sed -n '/startlineregexp/,/endinglineregexp/p')
On the same note, I needed to find what form data a webpage was posting to the server. Was hunting around for tools, and yes, it is again a one line command. I so much enjoy moments like that with Linux
(ngrep allows you to listen in on outgoing traffic, like this: sudo ngrep "POST" tcp and port 80)