Sure. I've run multimonitor setup In linux before you could realy do it in Windows. (win98 could do it, sortof, but it was retarded). And actually I've using it right now on my desktop.
Hell I have a triple setup I use sometimes, 1 crt, 1 lcd, and 1 TV. Doesn't work out all that well though, due to the propriatory nvidia drivers. Much easier when you don't have to depend on those (but then you loose 3-d acceleration).
There are several ways to do it. The easiest to look up is xinerama. That sets it up so that you have 1 big desktop made up of 2 monitors. Other modes include having 2 seperate desktops you move focus back and forth with the mouse.
If your cards are well supported it should work out. I don't know what your on-board is, depending on that it can be very easy to moderately difficult (having to edit the configuration files themselves.) Nvidia on-board would make it moderatly difficult.
But if it's Via vid card or Intel it shouldn't be to hard, but it's hard for me to know because i've never used a Voodoo-3 card in Linux, and I don't know your on-board.
Most of the time it will be detected at install time (unless you use a more primitive install type like Debian, Slackware, or Gentoo), and it will give you a chance to configure it. (which side is the screens are in relation to each other, monitor type if it can't be autodetected etc etc). If not then finding the display settings and mess with it their.
Worst case is that your just going to learn how to edit the /etc/X11/XF86Config or /etc/X11/xorg.conf file, but you'd probably have to do that eventually anyways if you use linux for any length of time. Nothing beats being able to get stuff exactly the way you want it.
For instance I have 3 setups so that I can use 2 screens, or all 3 (rarely use), or just 1. That way some games like ut2004 have a hard time dealing with dual cards, so I just restart X with the 1 screen setuip.
