1. city streets, bike lane, multipath
2. i don't think so. what do you do when you hear a car? besides i can still hear well, better than any driver.
3. i use the flat plastic strip ones that came with the walkman. they fit under the helmet.
4. books on tape. maybe you could argue this is safer but i don't care.

i thought that sense of smell crack was pretty funny, myself.

some people who use hearing to ride: www.teambat.org
they deserve there own thread though, they're pretty awesome.

i'm looking into an mp3 or something that can record lectures that i can listen to again. suggestions?