My arm hair used to bother me too. I tried shaving it off once, but then a friend of mine asked quizzically with an eyebrow raised if I had shaved off my arm hair. I suddenly felt self-conscious about NOT having arm hair! ha ha I started looking around and realized that no one else (that I saw at least) had shaved arms, so I never did it again. And hey, we already shave our legs. That's hassle enough, so who wants two more limbs to upkeep? ;) I say love your arm hair.
I HATE girls who shave their arms. It's just weird. And then if you don't shave it like everyday you can see stubble, which makes it worse. If you have dark arm hair that you're self concious about, you could always bleach it. I wouldn't know about how you'd go about that, but I'm sure you could pick up some kind of kit from walmart. If it's not dark and there's just a lot of it I'd just let it go. You're probably the only one who notices, and you're probably the only one who cares.