A quick bit of advice, if you want to extend the battery life of your Linux (and probaby windows) netbook and use Firefox, install Flashblock. It turns out when ANY flash animation is playing, the processor clocks to maximum and the CPU use goes way up. The faster the clock, the more power it uses and the more heat it generates. The nice thing about Flashblock is that you can decide if you want to see something like a Flash video you can, but most of the time you can just load a web page quickly and easily without sucking down the battery. What made me realize this was thinking about the iPad. It is very quick on the net, and the reason, partially, is that it does not run Flash. So, no Flash increases battery life, speeds page load times, and makes the machine look like it is blazing fast on the internet. You only really notice the lack of Flash on some sites, like Ikea and Rolex, both of witch are impossible to use without flash. Most of the time, it just blocks annoying ads.
Netbook tech note