I thought some of you might be interested this article.
I always put my iPhone in a case (and use a screen protector). In general, the case usually makes it less slippery; the case/screen protector to prevent scratches and maybe preserve trade-in/resale value.
I went without a case for years. I just recently when back to using a case because I dropped my phone and, this time, it broke. It broke front and back so replacement was the only option. Repair would have only been $30 if only the front had broken. However, this cost me $200 plus the time it takes to restore the phone. So, I’ve got a case. However, I found one I can tolerate. I found it on Shawn Blanc’s site, Tools and Toys. It may be the one referenced at the end of the article because it’s a little less than $10.