click Mrs. George H.W. Bush to enlarge
I brought this up at a dinner party last night and everyone scoffed. Yes, there does indeed exist a picture of a comely Barbara Bush [Senior] in a swimsuit (I was wrong about the Bikini part...they hadn't even been invented yet). There you are, Friendos.
 Well, they kind of had been invented, according to the wikipedia, but they didn't become popular until after 1943, when swimwear was under a restriction to use 10% less fabric. The wikipedia also has a great definition of a bikini: A bikini or two-piece is a type of women's swimsuit, characterized by two separate parts — one covering the breasts, the other the groin (and optionally the buttocks).
Here is a photo of one of the very first bikinis modeled by Micheline Bernardini.
In our more modern, Idiocracy, world, the bikini was finally reduced to the microkini (really, a glorified Band-aid®: