Dude, best thing to do on any phone is a screen protector, I have ordered one from eBay called XtremeGuard full body protector, very much necessary for this phone, also look into any kind of case for the back to keep it safe too, hear horror stories from some people who bought a N4 and I hear from some people they are very strong so it just leads me to believe that the back glass may have flaws in them that may be from batch to batch or something like that, so yes for protection, you may want to keep it bare but it is costly.
XtremeGuard full body protector is only $3.99 and it compares with that of the XO Skin but the XtremeGuard is a little harder if you use a stylus on it so XO is softer and they are $22.99, difference is is with the XtremeGuard you have to make your own solution of water spray that includes a little dishwashing liquid soap in it.