There's been a lot of articles and demos on minitabs recently. Minitabs are a subtle and easy to modify type of navigation list that can either be floated or centered based on your design needs.
Web graphics has a great article on
Inline Minitabs and a follow up titled
Float Minitabs. each article is linked to demo pages for easy reference.
The origin of the mini-tab dates from 2003 and a post by Dan Cedarholm at
Simple Bits. Here's a link to his
original post and an additional article detailing Mini-Tabs with
Background Images.One problem with the inline non-floated lists is that IE 5 won't show the bottom borders on your links. One possible solution to that is to give your links a height of 1em, though this moves them outside the UL element. I suppose it's possible (or inevitable!) that there are other complications as well...
A more complex example is the
Flyout Minitabs from
Aplus Moments. Pretty sweet.