I just did this google search. "3 monitors on a notebook laptop". There are several good hits. This YouTube shows exactly how to do it.
http://www.youtube.com/watch?v=gn9VZq-nDj8
He has an I7 nootbook (not slow) and is using an external mouse and keyboard so he can be positioned directly in front of his 3 monitors. He also indicates you can have more monitors and shows you exactly how to do it. I was reading the comments at the bottom of the video above and you have to make sure that the notebook(laptop) has a video card that can do this. So I guess you should get the hardward needed and make sure it can actually do it before you buy it (see it with your own eyes).
For anyone who does not currently have more than 1 monitor, this video may be helpful for showing you how to get the monitors in the correct visual order once you have more than one of them attached.
http://www.youtube.com/watch?v=Jf_TlAt1P9s