One of the things that I’ve missed greatly since moving to using a laptop as my primary machine just over 3 years ago is the ability to run multiple monitors. My old tower machine had a pretty hefty video card (for the time) in it that had both DVI and VGA connectors built in. At the time, I ran twin Dell 17″ LCDs off that card and loved the advantages that having twice the screen space gave me.
That all changed when I bought a Dell 17″ laptop and started using that as my primary machine. While you can leave the laptop open and use the internal LCD screen with an external monitor attached to the monitor connector, that configuration has never suited me well. I have this “condition” that things I deal with on a regular basis need to be symetrical (my wife thinks I should be in therapy for it, I think it’s just a matter of wanting things to look “right”), so having a laptop open next to an external monitor just never appealed to me.