If you buy a new PC or laptop these days, it likely to come with all kinds of unwanted junk: trail versions of antivirus, browser toolbars, CD-burners that replicate that the OS can already do by itself, and so on. There's a great little utility called The PC Decrapifier that can help clean this up. Its basically a script that searches the PC for 'crapplications' and then gives you a list of what it finds. You then choose the ones you want to get rid of, and it gets on with it for you.
I tried it on a laptop recently - it worked pretty well, uninstalling a bunch of things without me having to supervise it. Norton Internet Security put up a bit of a fight and I had to click a few 'Yes, I really do want to get rid of this' buttons. But apart from that it went very smoothly.
There is an option to send stats back to main site. The combined stats that have been gathered are pretty interesting - what are the most widespread crapplications, and which manufacterers are installing them?
The list of crapware that PC Decrapifier searches for is pre-defined, but on the web site you can vote for crapplications that you would like to see future versions hunt down. Amusingly, Internet Explorer has got some votes there. Even as a Firefox fan I have to admit that that's going a bit too far.