Thanks.
How about a X-33 type vehicle? Not the planned Venturestar, but a smaller version to be used as a quick reaction vehicle for personnel transfer and orbital rescue. I remember the main argument against the X-33 being the weight creep it was experiencing. If the planned payload were small (only people) then this should be far less of a factor.
IMO, this is how SSTO technology should be persued. Start off launching small payloads, and slowly buildup as experience and new technology pemit.