I started using bash in 1996 when I installed Slackware 3.1 on a Packard Bell 486 SX2 50 MHz machine. Eleven and a half years later, I learn about Ctrl-R to reverse search commands in bash. Granted, I'd been using ksh with vi bindings for six or seven intervening years. But I should have known!
Then, I come to find out bash supports all the emacs bindings. Not only that, so does TextMate. As does Cocoa.
That is cool! Now I'm gonna have to learn all the emacs bindings.