I'm also a huge fan of Mary Roach's writing and while I don't have any suggestions for other similar books, I do want to just throw in a recommendation for Mary's new book, "Packing for Mars," which JUST came out like two weeks ago. It's FANTASTIC.

Susan Orlean wrote a book called "The Orchid Thief" (which was turned into a famous movie called Adaptation about how it was basically impossible to turn that book into a movie.) Mary Roach's writing style seems very much influenced by Susan Orlean but Orlean has more subtle humor. There is science in the book (and history and just good reporting.)

Natalie Angier isn't as funny as Mary Roach but she's a great, accessible female science writer. I like "The Canon" although it's taking me forever to plow through it. So much information.

Other funny science writers: Neil DeGrasse Tyson ("The Pluto Files" made me laugh out loud) and Phil Plait

I enjoyed the Angier also and had the same feeling---plenty of info, but not as witty. And yes, Packing for Mars was more of Roach's awesomeness. I will check out the Tyson though...

Oliver Sacks is an amazingly accessible, yet witty, science writer. Try "Musicophilia", "The Man Who Mistook His Wife for a Hat", or his wonderful autobiography, "Uncle Tungsten: Memories of Chemical Boyhood".