Hummingbird looks like it has potential. I currently use a product called Woopra: http://www.woopra.com/ to do the same thing. It's a solid product but gets expensive when my sites get a lot of traffic (they only give you 30k pageviews a month for free). Once hummingbird matures if it gains more of the functionality woopra offers this could be a viable DIY alternative.
You should check out my take on this: http://chartaca.com
Free, as many charts as you like, and no data limits! :)
Just a word of warning ... it's barely even an MVP at this stage. More a sort of experiment to see how far I can push one of those free Amazon micro instances (pretty far when you use node.js as it happens!).
