Love, love, love! I can do 4" but its a big difference between doing 4" when you foot is size 6 and size 10 (me)! I got some new 3" heels for $20 w/shipping and they're my new favorites. Figured I'd share where I got them:
6pm dot com
The prices may seem a little expensive at first, but if you sign up for their email discounts you get crazy low prices... but you have to pay attention. What they do is they send out emails where the prices are super low (12.95-19.95), but they only last for one day! They have sizes up to 12W on some shoes, depending on brands. But shoes that were out of stock in larger sizes on other sites were in stock on 6pm. They also sell clothes and stuff there, but those aren't nearly as cheap.