It might be interesting if you could store the blockchain and wallet.dat on a rewritable bluray disc instead of your hard drive. Then you could simply use bitcoin from any device that accepts bluray disks and bitcoin.
Exactly my thinking...
Hard Drives fail and burn out.. but if you keep a disc in a nice sleeve it will last forever.
That way it would also be alot easier to physically store your bitcoins.. rather than a decaying thumb drive; a stack of blurays!
Its my opinion that any online wallet or computer wallet is at a huge risk and you would only use those as a buffer between your bitcoin use and bitcoin storage
Forever until the first fire turns it into a Frisbee.