Just ran across some diamond hole saws at Lee Valley Tools. Not is cheap as on ebay but I'm sure they're high quality from Lee Valley.

Took Seahorse Fanatic and myself about 90 secs to drill 1" bulkhead hole with powerdrill and a hose. And you end up with a much cleaner than using a dremel bit.

princess auto has a sale from april 24-mai6,
5 piece diamond hole saw kit with pilot bit for 25.55

Or you could just order them here.

true enough but 5 bits for 26 bucks you cant go wrong...it is only a sale though