I just checked the United Mobile web site for somebody and discovered that now they are selling sim cards and recharges denominated in USD and GBP as well as euro and it looks like you can choose your currency when buying the sim card and then recharge in that currency.....interesting, though, CHF not included!

Has anyone tried changing the base currency of their card? I'm fine with the Euro but I may send UM an email and see if it is possible to switch to USD. If you have to purchase a new SIM then it probably isn't worth while (for me).