Since my background is in web development something came to mind when looking at bitcoin and the bitcoin addresses.
For the sites like xkcd which may accept donations or for other individuals with personal sites.
What about adding a standard for bitcoin addresses in a <link> or perhaps in dns. Like how it's done with OpenID delegation (though OpenID uses <link>, http headers, and there was another bigger format for it you could redirect to by the accepts header), or SPF does.
Something like:
<link rel="bitcoin" href="urn:
bitcoin:##################################">
<link rel="bitcoin" title="Your Name Here" href="urn:
bitcoin:##################################">
Or a dns entry: example.com IN TXT "v=bitcoin ##################################"
The idea would be to enable bitcoin address discoverability. For the many of us with a web identity, instead of saying hey just donate to my bitcoin address "##################################" being able to just say donate to "my-web-address.com", and bitcoin clients understanding that and like with how in OpenID "my-web-address.com" normalizes to "
http://my-web-address.com/" the bitcoin client would check for a dns entry, then try fetching the page and looking for a rel=bitcoin <link>. Someone's bitcoin address could be discovered. I know there is IP address support, but I don't think I'd run a bitcoin client on my web server, and that kind of idea gets really screwy on a wider scale when you throw dynamic ip addresses (whoops you just donated to someone who happened to get assigned the dynamic IP I just lost) and vhosts (You donated to me? No, I don't run a bitcoin client on that ip...... Yup, I guess you just donated to a completely random person who happens to be on the same shared hosting server as I am).