im going to get a longer Ethernet cable this friday because the one i have doesnt reach my ps3 and i dont have enogh cash to buy a wireless router i wanna know if its possible to use my RockBand Mic to communicate woth other players in online gaming.

I am pretty sure that will not work. First off, the Rock Band Microphone does not have an earpiece, so I don't think COD4 would recognize it as a headset.

I also know that games like karaoke revolution, singstar, and rock band all use different microphones that don't even work with other singing games. Therefore, I am almost positive that COD4 will not recognize a Rock Band Microphone as an accessory and it will probably ignore it.

Good luck though.