[dfx-]

Any resource anywhere of 'cool' chemistry images for suitable avatars etc? Most that I find are too small or too big on Google etc..

[Blame FeliXe's avatar of adrenaline (iirc) for me thinking about it ]

[Yggdrasil]

You could try making your own following some of the instructions from the (ongoing) series on this blog:

http://chemicalmusings.wordpress.com/2007/05/09/how-to-make-pretty-chemistry-pictures/