Display pledge in local currency.
This may be of use for a small percentage of users but seeing the pledged amount in the local currency it would be great for international users. Of course, one can make the conversion by head, but my intuition is that psychologically is easier just to see the right amount. And it's great for weaker currencies than the US Dollar, seeing 5 USD is not the same as seeing 25 ARS!
Again, this is only relevant for international users, so I don't think it's high priority.
I would really like this idea - it does not need to be an exact conversion, but seeing the amount in £ would be a bigger incentive I think than seeing it in $.