The keys on my N95 are very thin and, although they have a central ridge that makes hitting the right key easier, it doesn't make hitting them at all any easier. This is the one thing (maybe two, considering thickness) that I preferred about my old Samsung 701 - it had nice big pieces of plastic that even the most ham-thumbed could belt with confidence.
The problem is that when I last cut my fingernails, I somehow managed to miss my right thumb. The fact that I did this at all is faintly hilarious, how I did it is faintly puzzling, but I did it. Unfortunately, my right thumb, me being right-handed, does most of the typing. And because the N95 keys require a fairly pointed approach, which means thumb-tip, I am now hitting it with the thin and slippery thumbnail and not the spongy and grippy thumb tip.
Which is faintly uncomfortable and bloody annoying.