I definitely need covers for my gadgets. My Sony 350 has a cheap red cover that I bought on eBay. It adds a little bulk but I find that the reader actually feels more comfortable in my hands with the case on. Plus, I usually carry it in my purse. There is way too much stuff in my purse for me to carry my 350 naked.
My phone also has a case. I haven't dropped my e-reader but I am prone to dropping or knocking over my phone. So a case for my phone is an absolute must. Plus, I really like the look of the case. It's a hard pink Body Glove case with grey accents.
So I guess I can't join this club.