Eric Ries is well known for mixing Agile with Customer Development to create the Lean Startup process. Here is a link to a slide presentation he created: http://www.slideshare.net/startuplessonslearned/eric-ries-lean-startup-schematic-view-of-agile-development-and-customer-development to the website for his upcoming book: http://theleanstartup.com/ to his blog: http://www.startuplessonslearned.com/ and to the book pre-order site where he practices lean startup by iterating on the screens potential purchases see: http://lean.st/ When you mix Agile, Customer Development and Alex Osterwalder's Business Model Development http://steveblank.com/2010/11/15/creating-startup-success-customer-development-business-model-design/ you get a very powerful methodology.