Chrome: Maybe you hate OS X's pencil-thin disappearing scrollbars. Or perhaps you wish Windows' scrollbars were less intrusive. Maybe you just want yours to be hot pink. Whatever your gripe is about Chrome's scrollbar, Rescroller can fix it.
Once you install the extension, you can edit Chrome's scrollbar's width (up to a maximum of 30 pixels wide), colour and even background image. If you notice any sites that don't behave well with the edited scrollbar, you can add it to a list of exceptions that keep using Chrome's default. You can come up with some pretty silly combinations, but it's actually a pretty useful extension if you want your scrollbar to be easier to click, or to disappear to save screen real estate.