I have a friend who recently got work at the USPS as a mailman (mailperson?). I know it's not glamorous, but he told me they're hiring again for those type of positions (after not doing so for a while). It's a fed gov job with benefits. FYI.
Mail carrier is the official term, I think (my mom works as one and just got promoted to a regular carrier). USPS is, in fact, hiring quite a bit for various positions if people need temporary jobs. I mail lots of stuff from selling on eBay and talk to the clerks at the counters and they told me about some positions that were open.
Re: networking, it's all really just about (a) getting people to like you (b) that have connections (c) to places that are hiring someone at your level (i.e., an associate with 0 experience). All three have to be true for networking (whether informational interview, "organic networking," or otherwise) to yield an interview. That doesn't mean you shouldn't talk to people that can't get you anywhere (don't be like the stuck-up people in DC), but I've lost count of times where (a) I shoot the shit with associates for a while knowing they have no real pull anywhere, just to hang out and learn a bit more about what it's like to actually work and (b) I talk to partners and they tell me to pass them my resume and they'll pass it along, and they do but the firm (or the partner) gets back to me and says that the firm just isn't hiring. But then, there are the the few times where I talked to a partner, had them either pass my resume along or send an e-mail to someone in charge that I send my resume to, and a couple days later recruiting contacts me to set up an interview. Yes, that actually happens, but the chances are low because all of the above (a, b, and c) have to be true for this to work.
Random sidenote, I think I've finally come up with a half-decent strategy to interview in markets I have zero ties to.