One caveat: best technical recruiters are former programmers (it's an automatic plus if a recruiter tells me "I'll take your LaTeX resume, I used it a lot in grad school").
I got called from Google during 2006. The HR guy screened me on the phone with all TCP/IP questions. I was amazed because he knew so much about TCP/IP and UNIX socket. It turned out that he was a former software engineer in Bell Lab/Lucent. It has been the best initial phone screen that I ever have.
One of the latest tactics that the headhunters have been using is to begin with a line like ``Hey, I used to be an engineer! But now I'm hanging out here doing recruiting, cool huh?''