Is it possible to use the PS Vita s data only sim card in an iphone 3gs?

I would like to be able to use my old iphone as an ipod with 3g any options?

Yes, whether your in the UK or the US, it'd work but it'd be pretty expensive. The UK version isn't SIM locked. People use iPad SIMs in Vitas to avoid unnecessary fees, and your doing the opposite which is stupid. Use the SIM in your iPhone then get a 3 SIM, and get all-you-can-eat data for £15. Then set the APN in settings to three.co.uk and leave the username and password sections blank