Some people are actually *gasp!* still using these laptops, and finding that they need to get a little more life out of them by adding some RAM.
For $60 I have just (literally today, although I ordered it a few days ago) put 4GB (2x2GB) of Kingston RAM in mine, and I am quite happy with the ~3300MB I am getting, because it is still 1300-1400MB more than I had with just 2x1GB, and for a lot less than buying a whole new laptop when this one is fine for my needs right now. Also, because I used matched memory sticks, it runs at full speed rather than some hobbled speed due to mismatched RAM.
I also get a FULL 4GB under Vista 64-bit, but this is not usefull as my Adobe CD3 isn't fully compatible with 64-bit Vista, and it is one of my primary applications.
This is due to the fact that 64-bit operating systems map around the memory hole that the hardware devices create in the 4GB address space. Because 64-bit OSes can address more than 4GB, what is happening is that you are using more than 4GB of address space. In my case, the first ~3300MB is mapped to physical RAM, then the rest of the first 4GB of address space is mapped to devices due to the chipset's requirement to map them into the first 4GB of RAM, then another ~700MB of address space is used to map the remaining physical RAM. The same thing happens in an 8GB machine with a 64-bit operating system, _if_ the chipset is limited to having physical devices mapped into the first 4GB of RAM - you still get 8GB instead of 7.3GB because the operating system maps around the physical devices to accommodate the full 8GB of physical RAM.
This still backs up my statement that the problem is with 32-bit XP (partially), because it does not have the capability to _address_ more than 4GB of memory so it can't map around the physical components to give you the full 4GB of physical RAM, like 64-bit OS can.
Don't worry if you don't grok memory management enough to understand how that works, just be satisfied that it does and enjoy it if you can.