[potatolicious]

This would be very cool as an interactive thing where you can select your own center. Hell, it'd be great for apartment hunters who can just select wherever their work is and go from there.

[natrius]

Mapnificent might be what you're looking for: http://www.mapnificent.net/

[crazygringo]

Wow! What a totally crazy and awesome tool.

The "bubble map" you get is quite clever.

Would be even more interesting if you could overlay different commute times, e.g. in 5-minute intervals, and produce something topographic-map-style.

[michaeltoth]

It's a bit slow and prone to crashes, but mapnificent is a decent tool for this: http://www.mapnificent.net/