SSD will give you no increase in browsing performance. As stated above, adding another 1GB of RAM can help, but it will not be day and night difference. If you just browse the internet and do nothing else and it seems to be smooth, then adding more RAM should help because that means the OS. your browser and whatever word processor you are using are all fighting for the limited 1GB of RAM.
The Intel Atom N270 is a dated single core CPU that needs to struggle with bloated software and a bloated internet full of Java code running in the background and Flash video ads.
So should I even consider upgrading this netbook? Or is it too outdated? What about the new Intel Atoms (N2600-N2800)?