Comparable salaries for Linux people?

[richb-RBmg6HWzfGThzJAekONQAQ at public.gmane.org (Rich Braun)]

As y'all know I've often posted here looking for staff.  At the moment I have
5 open positions (no, I am not looking for a ton of recruiter calls!).

One of the reasons I have these openings is growth of the project.  I'm
posting about the other reason:  a non-stop onslaught of poaching by
high-paying firms in the area; I've lost 3 of my best people in the past 8
months.  All of them found greener pastures not far from my Kendall Square
office.

I'm starting to believe my HR department is getting tremendously incorrect
salary-comparison data and that 2010 is shaping up to be a banner year for
tech compensation at least for Linux people in greater Boston.  Where can I
turn for real data about what the likes of Microsoft, Google, MIT/Harvard,
Genzyme and all the others are paying people here in the Kendall Square and
route-128 area?  If my HR department has its head screwed on backwards, I want
to get them un-screwed.

-rich