Flooring Tile - Diagonal Tile Marker (tool to help with tile cuts)

Does anyone know where a person might obtain a tool that will help with diagonal tile cuts? We are laying tile the week after Christmas and could really put such a tool to good use.

Thanks,
Sandra

Sandre---
If you install your field then come back and do all your cuts you can use a pice of tile as a templet to do your cuts....
Lay the piece you want to cuy on top of the top of your last piece you installed..Then take a pencile on the edge of your tile and slide it across and that will give you a perfect cut piece.....(yea!!!!) You can make a templete out of wood to make it lighter and easer to move around!!!
Woodman

You can also use a carpenter's "speed square". They come in plastic or aluminum, are about 6" x 8" and are triangle shaped. Lay the long edge on the wet saw stop while cutting and you will get a perfect 45 every time. They are sold in every store which sells tools.