What sneezles and squeegee are referring to is an article that Denny posted a couple years ago based on some research that a yeast guru did( don't remember the yeast guys name). It's about pitching an actively fermenting starter at the high krausen stage. Even though you may be underpitching, based on a Mr. Malty calculation, the yeast is highly active and takes right off without a significant lag period.
So, what I (and I suspect quite a few others) do now, is make my starter no more than 24-36 hours before brewing and pitch the whole thing at high krausen. If I'm doing a lager and need a higher initial count, I'll start it several days before that, and step it up, but my pitch is still in the active phase.