GigaByte is soon to be releasing what they call 'iDrive'! Based around a PCI card the new iDrive is in concept a Hard Drive that uses any RAM from DDR266 upwards, utilises a SATA interface build on SATA1 standards! Check it out > http://www.tomshardware.com/storage/20050907/index.html Looks promising although i would like to see alot more then 4GB's !
kinda dumb, ram doesn't last as long as a hard drive and 16-hours (when battery is in peak condition most likely) isn't much. Anything important-HDD it up.
What would be truly good is having static RAM solid state storage. Static ram uses transistors instead of a capacitor and transistor to hold bits. Meaing that they don't have to be refreshed like DRAM. But they're expensive as hell.