Debit cards are very hit and miss. They can be country specific, my Irish debit card won't work in the UK or anywhere else in the world. I can take money out of the ATMs but that's it outside Ireland. They're also not great for online, despite my card having the laser, solo and maestro logo on it, it won't work on any website unless that website has an Irish banking provider.
www.hostelworld.com has all the symbols but it's an Irish company, I know it accepts Irish laser, I'd assume they'd accept most other countries as they're geared towards international sales.