First salary calculator I've seen that was worth a damn. They didn't demand my email address, they asked relevant questions, and they separate by geography.
I'd prefer to just give my info and then see the salaries in each of the cities... but this works well enough.
Very interesting to see the different numbers of expected offers for the different areas.
According to this I am underpaid by roughly $30-40k. Ouch, well at least I love my job.