Ok, I feel your "pain" lol. I always want to return compliments, but like Elle I can't make myself lie about it you know? So I search frantically for something I like about the other person...it may have nothing to do with their hair. I've done shoes, dress, I've even complimented the other person for complimenting me! lol (like: wow! That really made my day, I wasn't too sure abt this style...thanks for commenting).
Compliments usually aren't too bad for me though...there aren't too many people around that don't have anything positive for me to comment on. What gets me are the: I wish I had your hair! exclamations. Like...um, ok. I'll let you know when I'm done using it? Wtf? lol