How Many Momitors/Dispalys? - MacBook Pro and Logic 8

I have a MacBook Pro 17" Dual Core @ 2.33-GHZ with 4 gigs of RAM.

I have an external monitor connected to my NacBook Pro which gives me two monitors. This is much better than just using the 17" laptop monitor alone.

Does anyone know if another monitor can be connected and how would you go about that?

I have limited vision and another monitor (yes, three monitors) would make life easier in my amateur song creations in Logic 8.

Thank you in advance,