Line length is a point that wasn't addressed. I try to keep my lines within about 70 characters when writing code, on the off-chance that someone with an 80-column editor and 8 spaces of code numbering (like, say, vi on the server console) ever has to read it. I can only wish that some of my colleagues, who like small fonts and large windows (and therefore have no problems with two- or three-hundred column lines) would feel the same way.

As an aside, this sort of issue crops up even between programmers who use the same editor, but differently configured. At work, I use a rather heavily configured vim, a couple of other people use similarly (but subtly differently) customized vims, the sysadmin likes his nvi session to be as close to Joy's as it can get, etc. "Your code is unreadable in my editor!" "Use my editor instead, then!" just doesn't cut it.