UV/Skylight filters are, if anything, a personal preference. If it makes you more comfortable knowing that a filter is on, knock yourself out.
I concur with J.T., it is silly to go out and buy an expensive lens just to throw some cheap UV filter on the front of it...It kind of defeats the purpose of buying high-quality glass, doesn't it? I am just an advocate of lens hoods, they provide the most protection, they are cheaper (generally), and most importantly, they WORK...Not only as protection, but by reducing the amount of stray light that enters the lens.
To most people, the sky is the limit. To those who love aviation, the sky is home