[amohr]

I use notecards - I keep a stack of blanks in my bag. If they're not particularly actionable, they go up on my blog for such things(http://mohrslaws.com/Lifein3x5), otherwise, they go in the to-do pocket. If they don't fit in either, I fold them into an origami frog, draw a funny face on it and leave it by the wayside. (http://tweetphoto.com/12387364) - This is also the format I use for my business cards.

If I ever find myself wanting for something to do or ponder, I just go to the to-do pile and browse.

I like the physical aspect of this system. To me, the important thing here is getting the ideas the hell out of my head - it gets kinda crazy in there, it's no place for a delicate thing like an idea. Plus having a big, unsorted stack makes them more interesting to browse.