Recently I got a Bluetooth headset for my PS3. I like it, great sound. I think it's nice to get to talk to my friends while we play. But when I play Black Ops online, I wanna be able to talk to the other players (who aren't my friends, you know, when you play with strangers) But I'm only 12. So what I wanna know is, will people make fun of me if I talk and they know I'm just a kid? Or will they not care and talk to me just fine?

A majority of online players will take advantage of younger kids that play and make fun of them because of the sound of their voice. I know because I've been playing for 4+ years and used to do the same thing lol. I know what you're thinking and yes it is mean and hurtful but it's the truth.
My advice? Just stay away from them. If you find yourself in a lobby with these douchebags then leave and find another. The only thing they can do is use their words to try and hurt you. There are people out there like you that would like to find some friends to play with without having to deal with these types of people.
Girls are pretty nice, too.

There is no type of microphone that will change/mask your voice. Only puberty will inhibit these changes.