My commuter bike weighs 26 lbs equipped. It's an '84 Peugeot.

I bring my cellphone, a USB thumbdrive and sometimes an ipod to my software job. I don't carry a laptop or papers. My bike has no rack and no panniers. I do carry a multi-tool, a small wrench, a patch kit, a reflective ankle band, 2 AA cells, and a pen in the seat bag.

My commute is short, one mile. After work I usually go for a 10 mile ride around town because I have my bike. I'm not loaded down with work crap, or any crap at all, and it's fun to ride out to the hill and back or go trainwatching.

I suppose if the balloon goes up while I'm out, I might wish I had carried some canned rations, a shovel, and some KI pills on my bike, but then again...