Successfully upgraded to 2GB today. After doing this (& removing several useless Asus preinstalled apps) the netbook works quite well.
The RAM upgrade actually quite straightforward. Took me about 20 minutes.
I recommend following this video http://www.youtube.com/watch?v=Ci3w3jvJIpA
, and buying a cheap iPhone repair kit for the tools required from eBay (Philips #0 screwdriver & plastic levers). The dummy SD card is also useful to wedge apart the casing without damaging it.