I am still thinking whether or not to buy memory for my Samsung NC10. So far, it works great with the original 1GB RAM. It is running dual boot Windows XP and Mac OS X Leopard 10.5.5 without any hiccups. In fact, it runs faster in Mac OS X. Windows XP seems to run slower and slower as time goes even though I did not install any programs in it except UEFA Manager 2000. All other programs that I am using with Windows XP are portable applications.
On the other hand, I installed several programs on Mac OS X and it is still running perfectly. Thus, I guess that upgrading the memory will be at later stage and may be not necessary at all.