Need help with internet issue

I got a new iMac for Christmas, and while I love it, I am having an internet issue. We have HughesNet, a satellite internet provider, that allows us 450 MB of usage per day. Since hooking up the iMac, we have exceeded our threshold at least six times, more than we have the entire time we have had the service. (More than four years) I was wondering if there is something that runs in the background of the Mac that uses the internet that could be causing this? I have turned off the RSS news feed, thinking maybe that was doing it. Any ideas?

Thanks for your help!!

Angie

I can only presume you are above the Arctic Circle or somewhere equally remote with that kind of draconian internet metering!!

You should probably also disable any automatic checking for email, any Mobile Me syncing, and well basically turn off the wireless card most of the day and only turn it back on to quickly check your mail. The rest of the time, stick to apps that don't need internet access to function (which would be relatively few of them).