A meagre 1 GB and my blasted three year old notebook is maxed out. I've had a number of conflicting reports about this - even the manufacturer's support personnel, one of their FAQ's, and both SIW and an old free version of Everest say that I can go to 2 GB, but other sources, including a different page on the manufacturer's site and Kingston RAM upgrade checker all say I'm already maxed out. If 1 GB sticks of PC2100 notebook RAM were cheaper, I'd go for it and accept the loss if it turns out that the BIOS won't recognize more than one gig but alas PC2100 RAM is still pretty pricey.
I keep being tempted by a new notebook but Vista isn't a route I'm ready to take - I played with a freshly booted notebook with 2GB of RAM and Vista Ultimate installed and after boot only 800 MB of RAM were free. I actually bought almost the identical machine (identically spec'd RAM, harddrive and CPU) at Christmas with XP Media Centre preinstalled and returned it (buyer's remorse - kicking myself now) and right after boot it reporting well over 1.5GB free RAM. Discouraging...