Yeah, I use it for plotting follower data for CustomerFind. The chart on the homepage (http://www.customerfind.com) is a screenshot of part of a user's controlpanel, and was rendered using flot. It was very easy to get flot set up, it plays nicely with the rest of my js, including jQuery. Flot is fast.

P.S. CustomerFind v2 is no longer focusing on AutoFollow, though the copy on the homepage reflects otherwise [http://customerfind.posterous.com/do-you-sell-a-product-or-s...]