I agree with Hammer, unless amended in your location, NEC allows GFCI's to protect gounding type receptacles, under the conditions stated. There are a couple of additional requirements. Each grounding type receptacle being protected by the GFCI must be labeled "GFCI Protected" and "No Equipment Ground". Also, the grounding termainals of the grouding type receptacles may not be connected together and to the grounding terminal of the GFCI (it may seem strange that anyone would do this, but trust me, it's not allowed). I also agree that it would be even better to have a real ground, and would point out that it is acceptable to run an idependent grounding conductor (as opposed to all new cable) if properly done.