Haha, funny you should ask...I'm with the ID consult service now. Every time I see a book mention "ID consult recommended" I cringe a little.
The Hopkins Abx guide is awesome, though. Great rundown of almost everything. The only problem I find with it (and most other references) is that using it requires a diagnosis in hand. Without that, it's tough to come up with empiric treatment options (or lack thereof).