Tweaks? You want tweaks? I got tweaks....
Try this site for just about everything about everything:
http://members.aol.com/axcel216/axcel216.htm
It'll take you a long time to view a fraction of what you find there!
If that's not enough, try these for registry hacks and information:
http://www.users.dircon.co.uk/~flibble/reg.html
http://www.regedit.com/
http://www.winreg.com/
Like tweaking easily? Then use the ultimate, expandable/customizable, easy-to-use, FREE! utility X-Setup. A quote from one of the more than 500,000 users of X-Setup: "X-Setup is to all other "tweakers" like a truckload of bricks is like to a pebble..." Get it at
http://www.xteq.com
Have fun!