OK, I've nearly completed 2 weeks just using a Netbook and I think it's a complete success. The experiment using a HP Mini 1000 running an Alpha version of Ubuntu Karmic proved I can get by without the need of a bulky and power hungry Laptop for all my day-to-day work.
The netbook worked out especially useful while I attended Linux Plumbers in Portland. It's light, compact and I got a reasonable amount of up-time as long as I judiciously used suspend/resume.
Will I be dumping my Lenovo 3000 N200 laptop? Possibly not, but I'm convinced netbooks are the way forward for easy portable mobile computing.