Totally unrelated to the artwork (which is vibrant!) but you might want to consider using something like the free standard edition of Google Apps to be able to have email at your vanity domain. From your side it works like using another gmail window, and for other people it just looks like whatever names you setup at your domain... so awesomesauce@daniedreams.com, for instance. And all free and google powered
I like the honeycomb tree thing. For some reason I'd feel like the back side ought to have a tiny B&W bee somewhere...