How much 'networking' and job-mongering goes on?

I would say there's a lot of 'networking' going on - in fact, for me it's an important aspect of the conferences (not just YAPC, or Perl conferences, there are other non-Perl conferences I visit), if not the most important aspect. For me, "networking" has resulted in (academic) papers, two jobs (including my current one), new friends, the discovery (over and over again) that people in real life are far more interesting and multi-facetted than they are as letters on a screen.

As for job-mongering, both YAPC::EU and YAPC::NA have had stands with recruiters/HR people for the past couple of years (typically for sponsors). Details vary a bit from conference to conference; NA seems to have more stands, but more limited (and sceduled) time, as in EU there are less stands, but they're there during the entire conference. And there are always people saying "we're hiring".