How do I plug more that two monitors to my computer?

"Easiest solution - If you have any other output such as VGA, get an adapter and use it.

If not, get a second graphics card and use that - you can just get the cheapest one that will fit - it should do the job.

Edit - As Shoeless said, you must use same manufacturer for Windows Vista, but I do not think there is such limitation in either Windows XP or Windows 7. If you are using *nix or anything else, I do not know in advance if it will work."

"There is also Matrox DualHead2Go and Matrox TripleHead2Go
they divides one monitor output into two(or three) so you can easily add multiple monitors.

And also external USB graphics cards"