Good Demo System For A High-Bandwidth Link?

FuzzyDaddy writes "My company is planning on demonstrating a 2.5 Gigabit per second link to some potential customers in the next few months. Now, we have all the equipment needed to measure how well the link is performing, but we'd like to put together a cheap 'Gee Whiz' demonstration. Surely other /.'ers have put together similar demos in the past. What combination of computers, network adapters, and software have you used to demonstrate high data rate links to potential customers?"