I'm only using it on my lap till my new desk comes in next Tuesday. Other than that, I just use it on my lap in bed occasionally late at night when my back is hurting. I don't feel any risk or fear from that, but then again the only fear left in me is social fear.
I have similar concerns. There really is no telling what the long term effects of radiation from a laptop are yet since we're the first generation to do this but I think it's more of a worry for men since their, er, reproductive organs with that valuable DNA is more vulnerable. I remember seeing lead "cups" advertised for men who put laptops on their laps.
I bought a brand new tempered glass/stainless steel desk for laptop to sit on while I await my new desktop money to arrive I rarely use a laptop on my lap but could care less if i did. I already carry a genetic illness that I would never want to reproduce anyways and since sperm count is NOT semen count, it has nothing to do with orgasms or ejaculation ability, it just makes it safer for me by lowering my chances to ever impregnate anyone lol!
I always used to put my laptop on my lap, until I heard about the risk of cancer from a few reliable sources. Though it may only have a very slight effect, I'd rather be safe than sorry. I also try to keep my cell phone out of my front pocket for the same reasons, maybe Im being a little paranoid here but I know intelligent people who do the same.