Symbol doesn't always work! All of the Greek letters posted here (and ribbons, for that matter), I can't see 'em. But I can see the letters in
my signature. I have the Symbol font installed on my computoy too, so that's not it--I think it varies between browsers. For example, when you see Alpha, Phi, and Omega, I see AFW.
There's a trick. Every font has tons more characters than you think. (My letters are actually in the "Georgia" font.) Go to Character Map and scroll a lot. There's a Greek alphabet hidden in there, I promise.
However, because I'm fantastic and generally awesome, I'm gonna copy and paste for y'all!
ΑΒΓΔΕΖΗΘΙΚΛΜΞΟΠΡΣΤΥΦΧΨΩ
I think this should work on Macs too--I don't know, I don't have my MacBook with me right this second.