That's the worst! I always keep a notebook in my back pocket for just such an emergency(lets me use downtime at work to put things in the right order, too).
If you've got a cell phone, they almost always have a record function; I've used that before too.
Petulant Child said:
I always wish I had a pocket recorder for those moments when lyrics just start going through my head..unfortunately even if I repeat them over and over I usually forget them before they get written down. I at least get the jist of a song that way sometimes.
Mardy Pune said:
Honestly most the songs I've personally written just happen when I'm playing the guitar. I'll find a riff repeat it, then another part comes and there's a song. The words always come when I'm the shower or walking down the street.
I've co-written songs with other people, bouncing ideas of each other when jamming. And again the words come to me in the shower or walking down the street. I've tried sitting down and writing lyrics but I just ended up walking off to have a cigarette and hang out with the dog or listen to some music.