David you have good points, but I beg to differ that English would be in the middle of the phonetic spectrum, I think it is more at the complicated end. Of course the Chinese writing system is way farther that way, but that is more of an exception among languages. One more difficulty with English language that I didn't mention yet is the actual vowel sounds. Not just the fact that there's no clear correspondence between writing/sound of them, but the vowel sounds are quite complex and unusual. In Finnish language we have all the vowel sounds of Thai and they can be combined freely. Finnish and Thai are basically 100% the same, except that we make some combinations that Thais don't do and vice versa.
Many vowel sounds of the English language go somewhere in between or off the Thai and Finnish vowels, and there are quite a few "sort of start with this vowel sound and then switch to kinda this sound" vowels when explained to a Thai or a Finn, going to the direction of imitating a style rather than saying out loud the letters. Combined with the fact that sometimes the letters you see represent this sound, are at other times showing for a different sound.
Why I'm such a คนขี้บ่น about this is that this really makes the pocket Thai-English dictionaries pretty useless for non-native English speakers and they seem to be quite complicated and easily erroneous for English speakers as well. When I first started with Thai I was in big trouble and soon found out that the only way to go is to learn the Thai alphabet. Anyway, the English language has the great advantage that grammar is fairly simple. With Finnish language it's logical, but still, a bit of a nightmare for any foreign learner, very very complex... We do miss some letters as well,for example we don't differentiate between v and w, but it's easy to explain in a dictionary using v and w.
Anyway I do think that teaching the international phonetic alphabet in schools might be good idea, but the "letters" in the system are quite peculiar though. I think teaching about the differences of the languages in the world would be good idea in schools around the world, one way or another. It would be more relevant than historical anecdotes which seem to be the backbone of school education after mathematics and mother tongue.
Oh, and one more thing. I think a cat is a แค็ต :-)