An "Honor Bar" is a small in-room refrigerator similar to a dorm fridge filled with small bottles of liquor, soft drinks, and fruit juices usually found in nicer hotels to give them more of a 'five-star' feel.
A lot of people find out the hard way that, though convienient, they are quite expensive with a canned coke going for around $2.00+ and the small airline bottles of booze somewhere in the neighborhood of $5.00+
The honor bar is inventoried by the hotel staff when the room is cleaned up and and anything consumed is added to the cost of the room.
So, that even a moderate amount of drinking can add up to quite a tab and this has surprised many a convention goer, who thought it was a complementary bar, at checkout.
Thanks for giving me the heads up Macabee, I won't invite you to any of my room partys...
"Gentlemen! You can't fight here...this is the War Room!" -- Dr. Strangelove