The Berkus Method - Valuing the Early Stage Investment.

From Berkonomics

You should be able to adopt it to most any kind of business enterprise if your aim is to establish an early, most often pre-revenue valuation to a start-up that has potential of reaching over $20 million in revenues within five years:

If Exists:	Add to Company Value up to:
Sound Idea (basic value)	$1/2 million
Prototype (reducing  technology risk)	$1/2 million
Quality Management Team(reducing execution risk)	$1/2 million
Strategic relationships (reducing market risk)	$1/2 million
Product Rollout or Sales(reducing production risk)	$1/2 million

  Once a company is in revenues for any period of time, this method is no longer applicable, as most everyone will use actual revenues to project value over time.