These are some ideas that might be implemented in the future
.oc file suffix#
It might make sense to have a file ending for OpenCoin messages, especially for CoinStacks. This would allow mime-handlers to pickup the file and treat them in a special way.
oc over html#
In theory a CoinStack could come as a standalone mini-wallet that would display the contents of the embedded CoinStack in a readable way, along with ways to renew the coins etc.
The problem is that this would make users open up and trust arbitrary html files.
opencoin.net web wallet#
This web interface could even be the hander for .oc files.