Can you put an iPhone 3Gs on the Virgin Mobile network?

As far as I know, it's not unlocked or jailbroken but if I have to get it unlocked I will.

I want to know if it's possible to put it on the VM network now that they are selling iPhone 4s.

Let me know?

No. Only phones purchased from Virgin Mobile can be activated on their network.

I don't assume thus. I feel that simply phones purchased from their. You'll be able to use your iPhone 3GS with The Virgin Mobile network.simply note the following:
With phones not bought from Virgin Mobile, they solely support voice & text.
· information may fit, however it isn't a guarantee.
· unlatched smartphones should have the browser & electronic messaging|electronic communication} settings manually organized if you're to be used for browsing or image messaging, contact Virgin Mobile for help.http://www.cellitused.com/