As someone whose life revolves around the web, this is something I constantly have to remind myself of: "Get off the computer and talk to people". Most people are actually really nice and perfectly happy to hear you out. It's much easier to be mean to someone via email or over the phone than it is to be mean to their face.
Setting up a table (or just standing and talking) outside a church or the local grocery store, coffee shop, park or playground -- anywhere people congregate -- is also a great, low-tech way to find volunteers.
Where's the funniest place you've ever recruited a volunteer or donor?