portable hard drive
I second netbook suggestion. They usually come with 160GB HDD and I guess thats sufficient most of the times, otherwise you can always carry with you pocket external HDDs, WD Passport rings the bell as extra storage.
I am quite not in with hardwares similar to NexToCF. I bought similar kind of 'photobank' in 2005 that could read almost all possible cards that time but as technology evolves, they don't support new cards, ending up just a piece of junk. My photobank doesn't even read 2GB cards. It recognizes 2GB card as 1GB card. It can only copy 1GB card successfully and takes 13 minutes to do so. The battery lasts for only 2.5 cards transfer.
Overall, it turned out to be waste of money. May be they have better devices now, still I would vote for netbook. Its more versatile.