While browsing Bob Rankins geekly update, came across a study regarding wifi, laptops and fertility.
Study with abstract and conclusions here (full text also in a tab on the linked page)

The conclusion of the study,

To our knowledge, this is the first study to evaluate the direct impact of laptop use on human spermatozoa. Ex vivo exposure of human spermatozoa to a wireless internet-connected laptop decreased motility and induced DNA fragmentation by a nonthermal effect. We speculate that keeping a laptop connected wirelessly to the internet on the lap near the testes may result in decreased male fertility. Further in vitro and in vivo studies are needed to prove this contention.