(Seen on the web.)
Written for the impatient/curious soul. When your new babies are a day or so old, or up to a week or so, gently pick one up so that it is held belly up. Make sure you wait for a time when they need to pee. Lick your pinky (yes I said lick your pinky!) of the opposite hand and gently tap, stroke the genital area (cool breath helps) til the baby starts peeing. If the stream lets out in a straight stream then it is a male. If it lets out straight but then goes to a heavy drip then it is a doe. Crazy? Well, sounds that way, but I have never had it be wrong. Use a different finger for each baby for obvious reasons. And try it a couple days in a row, to be sure. You have to catch them early, before they pee on their own. I like knowing what sex they are early on.
* Checking for Teats *
(From an experienced breeder friend)
Also, another way I have heard about sexing rabbits at only a few days old is looking for teats, I have been told that female rabbits will be born with visible teats and males will not. (You have to be sure and check before 3 days of age before they hair grows in making it harder to locate the teats)