If you're looking for accents and the like, you can get dozens of things by trying the alt key plus various letters/numbers/punctuation marks. For example, alt + e + e = é, or alt +m = µ.
Hahaha, nice! I never knew you could get at it from there! I had always gone through System Preferences > International >Input > Character palette. Now I feel like an idiot!
All you have to do is drag them in or copy and paste them. Easy as pie.