Depending on how much info/mobility you want from your tooltip.
If you just want a move-anywhere tooltip, check out LitheToolTip Doctor (
http://www.wowace.com/files/ ). This will let you move it anywhere on the screen, and has the nice addition of growing the tooltip away from teh screen edges w/o you haveing to make any setting changes.
If you want some basic info added to is such as Target and Guild Name, diToolTip (on this site I beleive) will move it to any specified location (top-right, top-left, center-right, etc), and add the above mentioned info to the tooltip.
For a wealth of information and options, you can try TinyTip (also on this site). Its a move anywhere, edit any information shown in the tooltip, including colors, what info you get, and what direction it grows. It allows you to setup what you see in the tooltip with various arguments.
So grab one of those and give them a shot.