In one of his books Charlie P actually advises people to use well-hopped, low gravity wort for yeast starters. He recommends boiling bottles, sanitizing caps, and I think you're just supposed to use a heat-tolerant funnel to pour the hot wort into the boiled (and still hot) bottles and cap it right away, leaving a little more headspace than you normally would.
Store them in a fridge and when it comes time to use them, remove the cap, flame the opening, pour a little yeast in there, and use a small drilled stopper (#2?) to put an airlock on it. If you're not using the yeast right away, once airlock activity starts just carefully put it back in the fridge.
I don't know if this is exactly how Charlie P wrote it, and I don't know how good of a method this is, but it sounds ok to me. I'm thinking of doing something like this make pre-made starters (kind of like NB's fastpitch canned starter). Brew something in the 1.035 to 1.040 range (maybe the second part to an intentional parti-gyle batch), add a little yeast nutrient, hop it to about 25IBU, and bottle it up. I'd still want to re-boil it to make sure everything is ok, though.
