I was wondering the same thing and in fact got some printed by the online company called Vistaprint.
To be precise I got A4 letterheads (25), Sticky notes (5), logo'd envelopes (25), desk calendar (1) and business cards (250) for about £30. The quality was acceptable and for future use I'd hit a print shop, get my logo designed properly, see proofs.
I've currently used up about 20 business cards. My intention is to use the other items as small gifts to those who hire me on contracts. Also, to have them available as part of a goody bag for a Software testing expo I'm planning. Obviously a few more than 25 though.
I have seen great quality items including pens, key-rings, caps, shirts, etc. as I'm sure you know - but I'm not convinced they're THE tool for getting the message across to my target audience and keeping AG Technical in mind.
Of course they may be just the thing; a subtle non-pushy reminder, everpresent by being practical to use and adding some form of 'value' to your business by being so, maybe people just think it's cool to get branded stuff for free...
hmm, thinking about it I do feel hard done by if a supplier doesn't come with the goody bag (take note)
Mark.