Is it possible to make custom scrollbars? I got plain scrollbars, which mess the design up, and would like to style them. I can do that, but only in IE (7), not in Firefox. Is there a way to do so which every browser’ll support?
Only if you hide the scrollbars and add your own using JavaScript.
Or if you used Flash (that’s always an option that works).
Other than those two methods, your stuck, none of the others allow for scrollbar customization. 
I guess using Javascript won’t be a problem, as long as the original scrollbar stays there if Javascript’s not available. Will have to figure out how to change it, but it can’t be that hard, now can it?
FleXcroll would be a nice place for you to start, the script defaults to standard browser display if not supported.