All the research was done on a Dell Mini 9, a decent representative of the world of netbooks. But the efforts to double battery life from about three and a half hours means the Dell Mini 9 has relatively poor battery life, below average for netbooks. If long battery life matters for your netbook tasks, check battery life on other netbooks before buying. I still count this as a useful tip, but grudgingly.
Tips for upgrading the hard drive and overclocking the processors miss the netbook point: these aren't heavy duty workhorses crunching huge amounts of files. Few people beyond those processing audio or video need more than 160GBs of disk space. Word documents and spreadsheets just don't take that much room. And speeding up the processor slightly will make little difference in your browser-based applications performance. If you need to run PhotoShop Pro on your portable computing device, you should buy a laptop rather than a netbook.
The best tip for improving your netbook? Install Google's Chrome browser in addition to whatever browser shipped with your operating system. Even Firefox, as good as it is and my personal favorite, loses the speed race with Chrome. Upgrade to Chrome, and stop hacking the rest of your netbook.