If so, how? Could it be implemented via a USB, Bluetooth or Wi-Fi connection?
Droidcam is supposed to do it over wifi. Qik is a good option if you don't need a computer in the loop.
Justin.tv just came out with an Android app to do video streaming.
It uses any data connection you have, but the faster/more reliable the connection the better quality you will get.
The IP Webcam app gets good reviews.
DroidCam is another option.
I've had very good performance from Qik. It can also buffer your video, so if your 3G/4G connection is bad, it will upload later when you have a better signal. WiFi is of course also supported, very simple, very quick ;-)