Well... I bought 8GB of RAM from CanadaRAM. Sure makes the 64bit Ubuntu VM scream! :-)

Kingston KTA-MB1333/4Gx2 = $76.00
    http://www.canadaram.com/Kingston/KTA-MB1066K2-8G.htm

One of the easiest purchases I have ever experienced. 
Clear description of the product, decent price, 48 hour delivery! 

Even easy to install... once I went to THREE stores to find a small enough screw-driver to remove the back of my Laptop.  Apple provides instructions here...


So... I have 2 x 2GB MacBookPro RAM to get rid of if anyone's interested...