Great designs. I have a question for you however. What is your incentive for putting
these great themes up for free? Do you use PHP or javascript code placed within the
markup for backlinks or such?

Nothing is "FREE" Martin,

Look in the footer of the template. There will be 1,2,3 link(s) to the sites who actually paid for the theme to be developed.

In rare occasions designer will have only link to his own site if he is looking to improve link popularity for his own site.

This is a good way to gain large quantity of back links if users do not alter the footer. Also you never know about the quality of the sites who will be using these themes...

I create the themes to promote my sites, in the footer, as well as freewordpresslayouts.com

I think they are great!! I think you Should have a footer link in for your troubles!! Nice work!

The first one looks good... thanks...