This idea first came up as I have a spare 2Gb DDR2 Laptop memory that can be used on my sony netbook, mine is VAIO VPC-W211AX/T model.
I thought adding memory would be easier as I look on bottom side of this netbook, there is a big cover that easy to open (only has 3 screws on it), after I open it, I was surprise, its only has an access to hardrive, not the memory.
and then I was assuming the access to the memory should be under the keyboard, then I tried to look the screw that hold the keyboard, after guessing around, found these three screws that hold it.
finally, after I removed these screw, the access to memory is wide open (but be careful with keyboard ribbon cable), replacing the memory was the easiest part on this process, its only has one slot, so basicaly I had to remove the old one (1Gb Memory) and replace it with the 2Gb memory.
hopefuly those picture above will save you some time when you upgrade your Vaio Netbook memory.