Looks like these bad boys are starting to show up on Ebay (refurbished, so likely from Vaio TX series), but at ridiculously prohibitive prices - $659 plus shipping.
http://cgi.ebay.com/TOSHIBA-HDD1584-80GB-1-8-8MM-ATA-100-REV-D-HDD1584_W0QQitemZ120032151395QQihZ002QQcategoryZ162QQssPageNameZWD1VQQrdZ1QQcmdZViewItem
To be honest, I’d love to upgrade from my current 60gb (which I bought grudgingly for $200), since I have recently installed Vista RC-1 (release candidate) on my TR3A and need the extra real estate, but certainly don’t see myself spending nearly half of what this notebook is worth for a 20gb upgrade. Some may ask why not just get a new Viao - honestly, because I love my TR3A (look at sig—plus it looks like it’s Vista ready!!—quite surprised since with the crappy video card on board these TRs, I never thought Vista would ever run), but also, I just don’t see any justification for shelling out so much money for so little improvement over what I have right now. Well, for those interested, you now have the option to purchase the MK8007GAH in North America. Enjoy.