It's easily recognisable even when small which is important for a logo and a favicon. I like the colours. And clearly it shows an amazing degree of artistic talent, the sort that could only be acquired in art school :)
Allow me nonetheless second some other commenters who observed
- the #\a concept is not obvious
- the keystone would normally be part of the arch, not under it
- the blue and black are difficult to distinguish in the small version
- while you explain the #\a and the keystone, the red/blue business is mysterious, and perhaps a tad decadent - art for art's sake and all that.
At a glance, it looks like the white bit has risen up out of the red bit (if you'll forgive the technical language here), and the blue bit is just background.
A slight improvement might be to make the horizontal edges of the #\a (top and bottom) a little thicker, to enhance the a-ity (although I can see that that might diminish the arch-ness). Another might be to use a brighter blue.
Are you planning to stick with this or are you inviting suggestions (not that the absence of an invitation has stopped me or anyone else) ?
