This is a little side project I've been working on that visualizes your TripIt flight history using treemaps, like the one you see in the background (more screenshots). If you have any problems operating it, please email me at firstname.lastname@example.org and include the full URL.
Enter your email address to below. In the following page, check "Grant Travel Report access to my TripIt data".
Disclaimer: I haven't spent time making this thing have bulletproof security. If you're a secret agent, you might not want to use this. Then again you shouldn't be using TripIt anyway :)