Here's another example of how the internet can foster the spread of misinformation. I happened upon a blog post that re-posted in full someone else's rant about why Christians should not use the word "Allah" as a name for God. To stop the spread of misinformation, I won't link to it. I fully agree with them that the current associations of the name as the proper name of the god of Islam make it unacceptable as a generic name for God. But why would English-speaking Christians need to use an Arabic word for God anyway? In today's world, it would simply cause confusion -- making it seem like the two biggest world religions really worship the same god (they don't).
However while the main point of the rant was correct, the post itself included a very glaring error of Hebrew etymology intended to discredit the word as a deity's name. They said that the Arabic word "Allah" was the same as (i.e., cognate to) the word for "oak trees" in the Hebrew Bible. This is completely incorrect. The terms are not related. The Arabic word is cognate to 'Eloah, a rare Hebrew synonym for El or Elohim, both used as generic words for "god." The same is true in English -- we can use "god" generally like "the Greek gods" or specifically as "God" to refer the Judeo-Christian God. One of the Hebrew words for "oak tree" is 'elah which looks similar to the Aramaic cognate of 'Eloah which is 'Elah. The spelling looks the same in my English transliteration, but there are differences in the original script. I suppose that similarity is possibly the source of the mix-up. (Side note on historical grammar: In Arabic and Aramaic, the last vowel in 'allah or 'elah is a historically long /a/. That's how we know for certain that 'elah "oak" in Hebrew is not related because historically long /a/ shifted to /o/ in the Canaanite dialects. This resulted in the /o/ vowel we have in 'eloah and 'elohim in Hebrew.)
At any rate whatever the origin of the word "Allah," it no longer carries a neutral connotation as a general word "god." As such, it would be inappropriate to use it for any deity except the god of the Quran. In the same way, it would be inappropriate to refer to any deity as YHWH except for the God of the Bible. One can read a good theological discussion of the differences between YHWH and Allah here. (that is, it's more articulate than the rant that I'm not linking to.)