Pull to refresh
A feature of some browsers (i.e. on Chrome OS and Android) that is handy is to pull down from the top to refresh. Technically, this is implemented with a vertical overscroll, much like the back/forward gestures are already implemented for horizontal overscroll. In Chrome, I believe this is just enabled on touchscreen devices, but if done well it could be very handy on trackpads as well.
Edited by Cassidy James Blaede