On the aspx file you can now work with the Validateable Check Box List just like you would with a plain Text Box.
I've got a Check Box List control that I want to require the user to check at least ONE box, it does not matter if they check every single one, or 3, or even just one.
It's easy to do this validation server side, but I am assuming you want to do it client side?
Nothing to install and it will be full supported in the next version of Visual Studio I think.
Don't know why but when the Check Box List is inside Update Panel and a partial post back is made..