Asus went with an AMI BIOS - and there are plenty of things that can be tweaked; however most of the interesting settings are under the Advanced -> JumperFree menu.
The main menu and SATA/IDE pages are pretty standard.
Under the Advanced menu, we can get to the interesting stuff - while most of the goodies are under "JumperFree Configuration", there are some useful tweaks to be had under "CPU Configuration" and "Chipset" as well.
It takes two screen captures to show you all of the features available under the JumperFree Configuration - it has it all; memory speed and timings, processor multiplier and FSB frequency, voltage tweaks et al.
The Advanced CPU settings also let you change the multiplier, and allow you to enable/disable virtualization, SpeedStep etc.
The Chipset menu gives you some control over the graphics slots.