A new online site, called SalaryShare, claims it can help you find out how much your co-workers make. This assumes, of course, that they are honest.
It works like this: you create a "pool" on the website and send the link to a few people who will anonymously disclose how much they make. Only people in your pool can see the link to the results. And you can do this with anyone really, even your social friends.
Of course, do it at your own risk.