On Sun, 24 Sep 2006 23:44:45 +0000, Andrew wrote:

If things are done properly, it
should be relatively easy to update the hardware to accept other types

There is a standard for RFID cards. I don't know if Oyster follows it.

I've seen a Singapore 'EZlink' reader in a convenience store with a
sticker stuck on the back reading 'dual band antenna fitted', so I presume
these things CAN be made to work with multiple card types.

of card in the future so we're not stuck with something completely
non-standard (as Oyster appears to be).

My Oyster gets a reaction out of Sydney (Australia) T-Card readers. They
obviously use the same system. However my 5 year old Singapore EZlink card
doesn't get a reaction of of a London Oyster reader or a Sydney T-Card
reader.
Sydney haven't actually got their smart-card system past being used as a
student bus pass. One day, Ill try waving a Sydney card at a London reader
and watch what happens, but not today, as the only people that have cards
are school students...