I found an alternative solution to this problem - Orange currently have a deal on a Sagem my220x handset which is 19CHF with a prepay card included with 20CHF onto it. So you're getting more credit than the price of the phone.

It's not a bad handset actually, quite light and very slim. It can't do pictures, MP3 ringtones or anything like that though. But as a back-up handset for whilst I'm in Switzerland it's pretty good.

And there are semi-decent call rates to the UK too.