I agree with you the Agile Marketing method is difficult to adopt because of cultural barriers. There are a couple places I recommend looking:

Joe Dager's blog: http://business901.com/blog1/can-you-have-agile-m...
Jeff Foley's blog: http://darksidemarketing.com/2009/12/30/agile-as-...

And ours of course: http://blog.marketbright.com/2009/12/06/agile-mar...