You can play Call of Duty online on Play station3 Xbox360 and PC (computer) But for PC and Xbox 360 you have to pay, for PS3 you don't have to pay it's completely free but you need a modem to play.
Yes if you have Internet connection, you can play people online
if you have a dsi, and are connected to the internet with Nintendo wifi connection, you should be able to connect over the internet, or if you have a friend you can play together locally.
No, you both need the game.
No, you can only play games on the Kinect if it's meant for the kinect, which Call of duty black ops is not meant for.
You can play online in Call of Duty Black Ops PS3 using the online split-screen support.
No. but you can play call of duty blacks online on a PC
no
you should be able to play it offline like ps3 and other consoles that doesnt require internet connection
No, but if you want your friend wants to play on a separate game system then yes. Also there is a splitscreen
you can play online with Xbox 360 and the PC. There are also other systems, but the Playstation Network or Xbox live is on the internet and not actually online gaming which Black Ops does not have.
No site without buying the game Call of Duty Black Ops or Call of Duty World at War
Could do