Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
Small laptops and netbooks make awesome network administrator's toolkits because they support wired and wireless network interfaces, deliver 6 to 8 hours battery life, and, like any PC have the flexibility to be configured however you like. Shop for your shiny new netbook carefully, because life is too short to fight with marginal hardware. You want rock-solid and dependable, not penny-pinching, minimally-speced, and flaky. I favor good reliable Linux vendors such as System76, ZaReason, and Emperor Linux. These shops are Linux experts that support Linux only. System76 offers a complete line of Ubuntu Linux netbooks, laptops, desktops, and servers.
Ubuntu's Natty Narwhal
Now we get into the fun stuff. Linux and free/open source software have a long heritage of sophisticated networking capabilities and cross-platform interoperability. Dig under the fancy wrappings on most any commercial networking product and you'll find open source inside.
Also: System76 Disaster