Can I use more than one nic?

[Dennis Wicks]

I find myself with several unused NICs (network interface 
cards) and some empty ports on my switches.

Would it be beneficial to have more than one network 
connection on a system?

If so, what would I do with it, and how would I set it up? 
Pointers to tutorials and how-to's would be nice!

Many TIA!
Dennis