At boxcar2d.com you can run a flash program which generates and optimises car designs to run over a virtual landscape.
Richard Kemp has written An introduction to genetic algorithms for neural networks, pointing to other useful resources. He used this technique to generate optimised steel compositions for use in Fusion power plant . (Phase transformations|Thesis or Cambridge|Dspace
David MacKay previously made a presentation “Why have Sex” based on his investigation of the rate of information aquisition by a species subjected to natural selection. The work demonstrates the advantage of cross-over in increasing the rate of information aquisiaiton.