WB 4 SmartButtons: What are they, and are they supported in any available skins yet?

They're a type of button where you don't specify any actual function as such. You give it a default function and tell WB that it's a smart button, which then means that using WB Config you can change the function of the button to whatever you want.
There's not a whole lot of skins that use them yet, but it's worth checking out Alexandries skins, as I think she used them a few times, if I recall.

Starone and Delicious use them too.

The best exponent of smart buttons is DavidK, in my opinion. https://www.wincustomize.com/window.asp?Cmd=AUTHORINFO&accountid=96

thank you every one. I will try each of these. DavidK's is wonderful. The thing loads web pages quicker than most WB4 enabled skins too. The smart buttons work as well. Like I said I will tru the others too. But it is going to be hard to beat this baby.