I was just writing some PHP and having the hardest time getting rid of a non-breaking space ( ) character in some HTML I was parsing. I finally figured it out: the page was encoded in UTF-8, and the encoding for a non-breaking space is 0xC2 0xA0. This is the code that finally did the trick (I also had to get rid of carriage return characters, hence the “\n”):
$string = trim( $string, "\xC2\xA0\n" );