If the background is white without a border then transparency is needed, otherwise it looks amateurish when displayed on a non-white background. A good example is Wikipedia. Pandora is almost the same but looks much better because the background is off-white and there's a border.
what is the size we can use 16x16? excuse the dumb question as I dont know a whole lot about it?"I hate to advocate the use of drugs, alcohol, violence, or insanity to anyone, but they always worked for me." - Hunter S. Thompson
I'm going to set the favicon back to the first EvC one, I'll try one of the other EvC's tonight, but I don't think EvC is it. It's the exactly correct information, but as an identifying icon it lacks something. The hand of God with DNA has that something but probably can't be done at that scale because too often it wouldn't be recognizable unless someone told you what it was.
I wonder if a frontal of a galaxy would look any good:
Darn, can't tell what it is. Thanks for trying. I just don't have access to my normal toolset while at work, so I'm limited in what I can do here. I can't easily upload images to the website during the day to see how it would actually look, but in this case I don't think it's necessary.