Mezcal vs. Mescal

Does anyone have a strong opinion or preference as to how this should be spelled? My browser spell check and Microsoft Word seem to think mescal is correct and mezcal is incorrect.

I see it either way in the news, and did a search:

mescal in SF Chronicle returns 41 results
mezcal in SF Chronicle returns 34 results

mescal in New York Times returns 616 results
mezcal in New York Times returns 10,000+ results

mescal in LA Times returns 84 results
mezcal in LA Times returns 48 results

mescal in Google search returns 508,000 results
mezcal in Google search returns 1,260,000 results

I prefer mescal, just because I like the way the word looks and it's easier for my to type. You?

**Update 2012: It appears "mezcal" has now become the standard. **