[georgemcbay]

300 minutes is the voice call limit. The data portion is "unlimited", so if you have Google Voice or are willing to move over to it, you can skip over a lot of would-be voice minutes by using GrooveIP (or some other SIP gateway solution) and serve most of your talky needs via voip without burning talk minutes.

Granted for most people it is probably easier just to bump up to one of the higher level Virgin plans which are also pretty cheap relative to industry averages.