Hello James,
Joel Spolsky wrote an article on his blog about some approaches to
hiring great developers.
http://www.joelonsoftware.com/articles/FindingGreatDevelopers.html
He has a great book out as well called More Joel on Software thats
worth a read.
I understand your reasons for not wanting to use agencies. Recently I
had an agency nipping my ear to go for an interview for a once in a
lifetime career oppertunity so I agreed even though I had no
information AT ALL about the job; just some generic specification with
things like 'good communication skills' written on it. Turned up at
the company in question 9am sharp just to find out they had no idea I
was meant to be there. Waste of time.
The agency was Quantium People so stay away from them for anyone who
is reading.