The first one is from Guyon Roche. The code is a little complicated because it feature some animation (looks great). Here's a screenshot but you should go to the link:
The second one is from Dynamic drive. This one simpler and I like it better, I have already seen some other sites use this style. The link also feature example, take a look if you like:
Of course, we will have some compatible issues with old browsers if we use these styles.