nVidia Optimus on GNU/Linux.
Features

    Full independent 3D on both video chips.
    Auto power off for second X-server and nVidia chip.
    Easy installation (look at Wiki).
    Multiuser access.
    Run in a way nvrun app.

Tested distros

    Gentoo amd64
    Debian Squeeze amd64
    Debian Wheezy amd64
    Fedora 16 (Verne) x86_64

Supported Models: All that supported by bbswitch, vgaswitcheroo (most of laptops with recent Linux kernel) + several by acpi_call (M11XR2, 1015PN, 1215N,
K42Jc, K52Jc, N53Jf, N53Jg, N71Jv, N73Jf, P52Jc, PL80Jt, U30Jc, U33Jc, U35Jc, U36Jc, UL80Jt, N53Sn, U41Sv, N53Sv, N61Jv, N73Sv, P31Jg, U43Jc, UL30Vt, E6420,
InspironN5110, XPSL702X, Vostro3300, Vostro3500, XPS15, ThinkPadT410, ThinkPadT420).

Video on YouTube: http://www.youtube.com/watch?v=c6RH69j-gMY&feature=plcp&context=C3f5cbeeUDOEgsToPDskLOX8DnELkwYsi2QZ7_phwJ