There's various paid tools to monitor rankings, but most are US based so can be a bit off when it comes to Google.co.uk rankings. If you're checking them yourself remember to 'disable search customisations based on search activity' - Google
Otherwise you may end up making big jumps up the rankings, but only in your browser
I use webposition it is better than google webmaster tools as this only tracks what you are showing up for and not what you want to be seen for, it also tracks competitors. It isnt free but it is cheap, highly recommend for professional use.
has everyone forgotten about google toolbar, page rank come as part of that, although annoyingly doesnt work with newer version of Firef......... oh crud just saw previous post dates, DONT BRING BACK OLD POSTS!! **taken to mental institution for saying this too many times, bloody noobs**
IBP is what you are looking for costs around Â£125/year, maybe more really can't remember but has an automated ranking checker just stick the terms in, which engines, and if you are us with thousands of keywords 2mins per keyword leave for 3 days.