Freelance jobs portals - A waste of time or a godsend?

My experience of using online freelance jobs boards has been pretty hit and miss at best so i was just wondering if I'm alone in this or do you find them to be a bit of a pain too?

I've mainly used people per hour and have been duped, propositioned (yes, I know!) blethered on to by a drunk and generally messed about. I have had a couple of good leads, but ratio wise I'm talking 10-1 rubbish over gold.

Is it just me or does this suggest that it really is who you know and face to face networking is the way to go?

Any comments welcome