Hardware

My Asus Zenbook's Elantech touchpad for example supports multi-touch properly - two finger scrolling, three finger window moving and maximize/restore via pinch, and four fingers brings up Unity's Dash.

Note though that there is another variant used in some Zenbooks from Sentelic, and multi-touch support for that is only in some git repositories, whereas Elantech supports lives for example in the Ubuntu 12.04 LTS kernel.