http://www.marketingsherpa.com/sample.cfm?contentID=3082

This article is about whether or not to demand consumer information before delivering content- more food for thought in the lead generation vs. brand building/identity building argument over delivery of web content.

This is a pay-for article:

http://www.marketingsherpa.com/barrier.cfm?currentID=3119

Basically, the sum up on it is: move your contact data capture to the bottom of the form.  They have done tests and shown that if people fill out information in the form (about the home they want to sell or buy, a credit eval, etc) and you put the contact information capture at the bottom you are more likely to get the lead than if you put it at the top.  The personal information capture at the top scares people away.