yes
yip this can be done.
It depends on what type of tv you have, and wether or not it has a DVI or a VGA pc input.
Most modern tvs come with a cable to connect it to your computer, but as with most of the world it is incompatible with Macs. You will need to buy a Apple cable that connects from mini-DVI or micro-DVI (depending on your Mac) to VGA or DVI.
You can also use the same thing if it only has S-composite video
I have set my iMac 24" 2.8GHz up with a 40" Sony BRAVIA.