Hi all, I just registered to reply to this.  I think this is a great idea, but I'm not sure if I'd trust a 3rd party for something like this.  Instead I'm picturing using the existing DNS infrastructure with a simple TXT record, similar to how SPF et al. work.  The format could be simple, just "BTC=<address>" (or maybe "BTCv1=<address>" to cover our rears for future expansion).

  You could publish your own records for your domains, you can publish dynamic or fast updating records using something like MyDNS.  It really makes it easy for anyone already doing business on the web (To complete your order, send the amount above to Order12345.MyStore.com), and you could still see 3rd party shorteners pop up.

  It would also have the advantage that no new servers would be needed, but when noagenda or someone else does implement an HTTP based service, it would play nice since they'd have a / and probably a protocol, so we could mostly differentiate without even needing an extra lookup.  In the case that we couldn't guess which protocol it was neither the extra DNS query or the HTTP request are huge performance hits.

  As a future enhancement, you could allow conversion of, say, email addresses into subdomains.  So you could send to person1@example.com, and it would lookup a TXT record for person1.example.com, or maybe something like person1.bitcoin.example.com for safety.

  I think this would be a minimal impact change, to try to resolve an address through DNS if it isn't a valid bitcoin address, but I don't know if I'm up to it, since I haven't delved into BT's code at all yet.  I'm sure I could offer a bulletproof implementation on the Linux command line version, using libresolv which (afaik) should be available everywhere without dependency issues... but I'm not sure off the top of my head what the windows equivalent is, and haven't touched wxWidgets before so that would add some time.

  If there's interest in this and nobody else takes it up, I'll see what I can put together at the beginning of November when I have a slot in my side projects list.

p.s. I just put up a TXT record in the above format on one of my email domains (perlstorm.net) for kicks.  If you're not familiar with DNS, either 'dig perlstorm.net txt' on a *nix or 'nslookup -type=txt perlstorm.net' on windows should get the address (as well as my SPF record).