V-Flyer

In what is possibly the first time in recent memory that Ryanair appear to have been stung by criticism, they are introducing free payment options with a prepaid Mastercard, and introducing a fee from 01 January 2010 on Visa Electron - a card that is slowly being phased out.

Not perfect... but much more widely available.
http://www.ryanair.com/en/news/gen-en-301109