somebody said you could detect it through bitcoin itself.
just patch your bitcoin to do > 100 or more connections.
when a new block is announced have a look at the sender.
if the first announce came from btc guild its most likely their block.
its not my idea. but i am currently thinking about writing a patch for bitcoin.
yup. i was just reading about that. at first glance it does seem like it could work.
in practice i am not sure. one is talking about milliseconds being the determining factor
in deciding when to switch.