Games that Support Dual-Head Setups?

Milo_Mindbender writes "It seems like almost all the new high-end 3d cards now support dual-monitor operation as a matter of course. I'm wondering if the game savvy people out there can recommend games (Linux or Windows) that have special features or modes for playing on a dual monitor system. I seem to remember seeing at least one C&C like game awhile back that let you have two views on the world (one on each monitor), there must be a few more that take advantage of this. Anyone know of any good ones?"