You'll find that the 1000 hour point is what you are going to need before you start sending resumes out. That is what most of the large companies are requiring before sending you an offer for an interview. I have heard of a couple of the smaller companies hiring with fewer hours, but were still looking for over 800.
I must differ with 'Revolutionary' with what he posted about experience. The number of hours of flying time will equate with your ability as a pilot as far as how well you fly, however, it has no bearing on weather knowledge, aircraft familiarity, administrative skills, customer service, efficiency, productivity, or commen sense. Those are all traits that a person has whether they are a pilot or not. No amount of flying time can give a person common sense, a person either has it or they don't. I know people that have wonderful administrative skills, but have no clue on how to fly an aircraft.
As Gomer stated, each operator is different, so find out what each one requires and send them a resume when you get them met.
Doug