Fair enough - as someone else pointed out in the blog comments, there's not a lot of "actionable" items in this post short of seeing if people work on side projects, which in itself isn't an indication of someone you should hire.

Word of mouth however is a pretty reliable way of finding solid developers provided you start with a good developer or two to begin with, and is a great way to build your team and culture - odds are if your team is recommending someone, they'll fit in with and extend the culture your company is going for. We saw an example of this when we opened our Vancouver office - after a few key hires we were able to attract a lot of talented developers who fit in nicely.