A workaround: the device you connect to has a bitcoin client running just to keep the block chain up to date. The USB key, upon connecting, syncs that block cha

A workaround: the device you connect to has a bitcoin client running just to keep the block chain up to date. The USB key, upon connecting, syncs that block chain with the one stored on the key. When you connect to a new device, the block chain from the key is synced onto that new device. Depending on how often you switch device / how often you use the key, this might or might not be a useful workaround :P.