I was going to write that I'd been to busy to add to the blog. But that's crap, I've been too lazy.
Lots has happened to me, I've got a new job at Direct Relations, a Marketing Agency, and I'm loving my new role of Senior Account Manager.
My laziness has had a strange effect on the PageRank for the blog. Last time I posted the PR was 0. I guessed that Google had been playing about again, the blog was fresh and looked after.
Nearly 5 months later, my PR is suddenly 3! I've done absolutely nothing to the blog. I know age of site is a factor in Google's algorithm but freshness is supposed to be one too.
As ever I have no concrete explanation.
I'm sure a better bet is to keep your site/blog up to date. Being lazy isn't much of a tactic whatever you do!