Aer Lingus do - Ryanair dont , you're going to need a prepaid Mastercard or a 3V card for the Ryanair booking , theres plenty of them around just do a search on AAM. With the prepaid mastercard you wont have to pay a cc fee.
They announced in December that they would begin to accept Laser on Jan 31st 2010, but I haven't paid using it. You could try a test booking & see if they do.
''Ryanair, the world’s favourite airline, today (22nd Dec 09) announced that will begin accepting Laser card payments on www.ryanair.com from January 31st 2010. MasterCard Prepaid will remain Ryanair’s free form of payment while other payment methods, including Laser, are subject to €5 administration charges.''