Device Analyzer
Large-scale research project by the University of Cambridge, UK. Keeps track of what happens on your phone and displays data concisely on the phone and periodically uploads anonymized data to a server. Logs minutes spent talking, texts sent, data transferred, wifi access points seen, etc. You have full access to your raw data stream (including your location trace!) through the website.
Work in progress and more statistics will appear on the website in the future! The researchers are open for suggestions and looking forward to constructive input from the QS community!