Once you've used a multi-monitor setup, it's almost impossible to go back to a single screen. Notebook users likely feel this pain most sharply. However, Village Tronic's ViBook proposes a USB-based solution for the folks looking for more display space.
Village Tronic ViBook: Multi-Monitor For Your Netbook : Read more
Village Tronic ViBook: Multi-Monitor For Your Netbook : Read more