I have a forum on my site that I coded, and on that forum people can use UBB type code to post an image that is hosted on some other server. So when that image appears on my page, say a 50 KB image, is that 50 KB added to my bandwidth totals? I had always assumed it wasn't since it is hosted elsewhere, but something someone said recently called that to question for me.

Why would that be added to your bandwidth.

Only if you are storing that image at your server and using it from there, then only the bandwidth will count for you.

If you are using something like in html:

<img src="http://userpostdomain.com/userpostedimage.gif">

Then it won't be counted to your bandwidth totals ..