But in Tonga, that means: no.
Seriously, Americans, I strongly advise you not to try to say Eyjafjallajökull. Not, that is, unless you know how to pronounce Icelandic. You can hear the correct pronunciation here. I'm giving you that link to scare you off, not to help you practice.
The efforts of Americans to say Eyjafjallajökull remind me of a man I worked for in the 70's, an ex-Cuban named Jorge. He was happy to be called 'George,' but one employee decided to respect Jorge's heritage by speaking the name properly. He called our manager Hoarr' Hey' (accent on both syllables).
We Americans do need a pronounceable name for this volcano. We need to be able to discuss it, because its effects may transform our world for years to come. There are very few new words that we find easy to pronounce, but here's a good one: It's the iAsh volcano.
Update: I hope this is a better pronunciation link.