Maybe the rest of you have known about it for ages, but I just heard of this site: http://www.omnicycles.com/ and, having had a quick mooch, I'd say it's definitely worth a look if you're interested in the scientific take on astrology. They sell software which plots the intensity of planetary aspects over the time-period of your choice. There's a demo which you can download to get more of an idea, too.

There's now a short interview with the creators of the Omnicycles program on my website:

www.astrozero.co.uk