Kegels and a strong perenium are GREAT for labor; they help control the emergence of the baby so that tears are less likely. They are also pleasant afterwords... being able to hold your urine as well as your uterus in is a good thing - and I won't harp on the previously mentioned orgasmic rewards. ;)

And I think my perenium is actually stronger after two kids than it was when I was a teenager; I didn't bother doing Kegels back then.