Milwaukee is known for it's brewing and Miller is one of it's best known brands. So if you're in the city and looking for something to do this is a great stop. Tours run every half hour from 10:30-3:30 daily (2 on Sundays) and are completely free (including tasting). For location and other information visit their tour information site. Here's a brief walkthrough of the tour:
At the start you'll be asked to show ID and get a wristband if you plan to taste, after that you join your guide.
Next you watch the filler lines where beer is poured into cans and bottles.
The warehouse follows where you play some beer trivia and check out their vast collection of products.
In the brewhouse you learn about the process Miller uses for its beer.
Finally the ice caves are a re-built example of how beer was stored before the refrigerator days. Originally caves ran under most of the brewery, but we're filled in when ice blocks were no longer needed. This part was re-done to give visitors an idea of what life was like back then.
After your tour, you get to enjoy 3 samples in the bar. Sit back and relax!