A twitter icon I made for a site I was working on. So far made in 4 colours, I'll add more as I make them (if I make them). I've added the large versions so you can shrink them to the best possible for your site with out losing detail!
You have my full express permission to reproduce, copy, use, edit and share the images in websites/games/emails/images. However I would love to know what/if you use them for anything so please drop me an e-mail at email@example.com and if the project you use them in makes you money then congratulations (you won't hear any complaints from me)! If you are using them in a uni/educational project however I do offer a word of warning for your sake not mine, do not claim you made them yourself as if they find out you may have a problem.