Deja Brew is one of very few places in the area where you can brew your own beer on-site. You choose the recipe, and they show you how to do the rest. You'll measure your grains, hops, and extracts, and use their large copper kettle to boil the wort and create a wonderful, tasty brew. They'll store it under the right conditions, and in 2-3 weeks you return to bottle your beer (and sample it, too).
The staff is very friendly and knowledgeable, and they're always happy to let you taste what's recently been brewed there. I've been several times, and it's always a great experience. On average, it would cost you $100-150 per recipe (which makes approximately 70 - 20oz. bottles).