Specialized Allez 2006 that I'm using as a commuter/touring bicycle
I think the crank arm has a crack in it. This is the best photo I can manage
http://img224.imageshack.us/i/crack.jpg/
You can't see it in the photo (camera phone), but there is a tiny little hairline crack right around where I drew the orange line.
I think it's a crack. it's along a pressure-bearing part of the bicycle. It tends to accumulate dirt, and when I run my finger along it, I can feel it, although I can't like put anything inside, and the bike still pedals as strong as every.
What should I do? About how long do I have before it falls off? Is it a problem? What should I do about replacement?