It’s great when companies like Capital Bikeshare make their data available. On their Trip History Data page they have stats for each quarter. I downloaded the most recent one, for 4th Quarter 2011, and created an interactive bubble map, trips4q2011.html, to illustrate the statistics.
The map is based on the one I created for Metro data (see Showing Metro Trips with a Bubble Map), but with expanded functionality. The CaBi data lets you specify registered users or casual users. A control at the bottom let you magnify the size of the circles used. At 1x magnification, a single trip is represented with a circle with a radius of 25 meters (an area of just under 2,000 square meters). Select stations with the drop-down menu or by hovering over it.
The list button will present a textual list of the data, sorting the station in descending order. The compare checkbox lets you compare two sets of values. In overlap mode you can manipulate a second set of bubbles, blue rather than red. The sum and difference modes compare the two sets, displaying the results in a single color.