As enthusiastic early adopter, I gladly work with the buzz of new products. On http://www.buzzer.nl anyone can register for free products and services to be able to try.
Buzzer is the first Word of Mouth Marketing agency in Europe. Where curious, articulate and socially active consumers be allowed as the first new products to try and 'buzz' to their environment. Click here for an explanation of Word of Mouth Marketing by William Sodderland.
On Frankwatching is also an albeit dated but very interesting article about Word of Mouth Marketing.