Yeah, the card on its own would be more compact, though also much more easily broken too.... I've always carried my travelcard separately as a hangover from the old days of the magnetic strip travels cards which they advised to be kept away from bank cards etc. It's also I think more covenient (and probably more secure) to carry it separately rather than taking out your wallet every time you enter or leave the network. I bought the Jimi when the plastic wallet I was originally issued with my Oystercard died - my Oyster is one of the early ones which has a separate photo ID card (I gather they scan the photo onto the card itself now), so I keep that in there with it, a few business cards and my Starbucks card. According to the paperwork that came with it, I should be able to carry four or five cards in there, as well as cash. Occasionally I keep the odd note in there (keep meaning to make it the home of an "emergency tenner"). It's a great gadget.