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!