Randomising posts

I was just wondering if there is a plugin that would allow me to build up a “bank” of blog posts and release then in a random order at a rate of, say, one a week, but at different times on different days. I would like to get a good mix of different subjects and types of posts, and whilst I know that even computerised randomisation is not truly random, I figure they are better at it than humans are.

The page I need help with: [log in to see the link]