Mac Air lasting 3+ hours

I am on this thing as much as possible.  I have generally found that unplugged and with a full charge, the Air is lasting about 3 hours and 15 minutes, +/- a few minutes.  I perform various activities on the Air including surfing the web, working with Entourage, an occasional look at a word or excel file.  There are times where I do walk away from the Air or I am doing something else.  This will typically extend the life of the battery.  Some days, the Air goes through two battery cycles, but that's because I am using it so much.  It's very easy to sit with it on the couch and do things during commercials or during boring parts of the program.