The new EU law (from August 2010) on payment services aim to protect the end user and for eaxmple to stop merchants from taking an extra fee when using credit cards and other payment methods (like SMS payments) for small purchases.
So far the law has not been testet and there is easy ways “around” for merchants. They can for example raise the price and give rebates for cash payments. It’s also possible that it’s ok with a fee if another party is responsible for the payment service, like with most SMS payments.
Best example in Sweden on how to handle this and to promote less cash is SL, the Stockholm Public Transportation. Paying your bus ticket with SMS is 30 kronor and with cash is 40 kronor. That’s the way to go.