I'm going to plug the Knowledge Vault (in my signature) again for more information, but for your convenience, I put all the links here:
Which Admission consultant company (cost/quality comparison)103-t55077Admission Consultant Services?103-t51753Admissions Consultants...103-t48543Value proposition of AdmissionConsultants:Feedback Requested79-t17908Admission Consulting firmsviewtopic.php?t=37570Any affordable admission consultants?103-t57623I personally think you don't really NEED consultants. Save the money for campus visits and other things. I came from a non-traditional background with almost no real-life MBA friends or support, and learned EVERYTHING through GMAT Club help and spending hours reading things here. If you contribute to good discussion on here, many of the current students will be willing to give you a hand by reading your essays for you, especially in the summer before school starts for the 2008-ers.
Hope that helps!