ok well i dont use one and ive been through only 1 new phone and my phone is in perfect condition. Its nice to have one case you scratch the screen or even use a case in case you drop however it makes your phone double the fatness and ive been taking care of my new touch for a year now and its still in perfect condition so its the matter of whether or not you drop it oir take care of it.
I use a case, don't never used a screen protector, nice to nkow I'm not the only one not to use a screen protector, but kind of thinking I should I proabably hould get one to be on the safe side -.-
i recently had one on my touch pro but took it off and havent had any problems when it's in my pocket or if it grazes against the floor by accident. It makes the phone much more responsive and easier to use and im so careful with my phone (since it's my first ppc) that i would never drop it.