daytum
I'm digging Daytum, the site from Ryan Case and Nicholas Felton "for collecting and communicating your daily data." The UI is a bit inscrutable at first -- you have to want to use it -- but once you understand it you want to experiment. The data capture mechanism -- and the underlying data model -- is flexible enough to support multiple viz's of the same data set, which should be fun...as long as I can figure out something more interesting to track than number of cups of coffee imbibed and number of hours slept. (Feature request -- ability to layer one data set on top of another...)