Webcam

Hey all i am going to be throwing a huge Superbowl party b/c i am close friends with some of the Seattle Seahawks players and we are throwing a huge party for all the families that arn't going to be able to go to the game. Anyways we are also looking to have either a live feed on to the web or a webcam program that will upload images every few seconds. We already have the website and everything i just need a program that would be good for this, oh ya and it needs to be mac compatible... Thanks all for the help