Woodlandbrew has a very interesting idea/plan. Please check out his blog for details that I am sure to exclude. Basically you boil your wort, put about ½ into the primary fermentor and the other ½ into another. Pitch your liquid yeast into the primary, wait 24 hours, which should be about the time krausen is starting to form, then add the remaining wort to the primary. In that first 24 hours, the yeast will multiply as they would in a normal starter so when you add the remaining wort there are enough yeast to ferment all the wort.
I just remembered one thing, which is why you should defintely check out Woodlandbrew's blog for the correct details, this works for a 5 gallon batch of standard ales around 1.060 gravity or below.
Here is the
link.