Here are some irssi</em> scripts that I've found useful. I'm must admit I'm still in love with command line and little tweaking even when it doesn't support a legitimate purpose. Or to quote Col. Jack O'Neill, its not about the fish it's about the fishing</em>.
screen_away.pl</strong> sets me away when I stop irc.
autostuff.pl</strong> adds all channels etc. to my list of channels.
window_switcher.pl</strong> makes it easy to go to other channels.
I tried nickcolors.pl</strong> but I got nausea soon. I hope irssi would start supporting 256 colours though.