case needed for iphone?

Should I get a case for the iphone or should I just use one of those screen protector things like invisibleshield? It seems like a case would take away from the beauty of the iphone and would add extra bulk


if I do need a case, what case do you suggest (that is very slim)

This is what I have on my original iPhone

I have a protective screen cover. The best ever. http://www.powersupportusa.com/products/iphone3G_antiglare.php

I also have an Incase case.

http://goincase.com/products/detail/slider-case-cl59056

a case is worth getting, found a fat scratch on back of my case and have no idea where it came from