If you do a lot of barbecuing and would like to have a super nice bbq barrel, Johnnyblegs over on instructables has a pictorial on how to build your own.
This type of BBQ is great if you have large get together because you can make a lot of food at the same time. I think my favorite barbecue was the time I went to a pig roast and they had a big barrel barbecue like this one and they roasted a whole pig with whole chickens inside it.
They had 4 or 5 different kinds of barbecue sauce to put on your meat as you wished. The chicken was really good cooked this way, super moist and tender, and the pork is always good at a pig roast. They grilled ears of corn in the barrel and had huge tubs of melted butter to dip them in. Really was the best.
How to Build Your Own BBQ Barrel