Netbooks have many virtues for use in the server room, they're easily portable with the potential of long battery times, have a keyboard & screen, and their toy-store class processors can run PuTTY on Windows XP/7. All that's lacking is a RS-232 port to plug a console cable into, an issue you'll find on almost all laptops currently manufactured. In laptop makers' defense, the RS-232 ports were a significant drain on battery life even when not in use and the removal makes sense for most users as the consumer computing world has moved onto USB, wi-fi, & etc but that does not help us.
The most sensible option for communication between current consumer hardware and the servers, network boxes and telecom equipment that commonly use console cables is a USB to serial converter. There's a catch as serial and USB don't always work together well [wikipedia explains further]. Knowing this I searched amazon.com carefully to find a solution to my server room needs and decided on the TRENDnet TU-S9.
I've had it for the last 5 months and used it on various Sun and Cisco equipment with no issues.