"Do you think I'm Indian?"
which usually implies, "Do you think I'm naive (or even stupid)??"
The origin of this saying, if I remember correctly, is Haydar Pasha's reply to the British when they suggested that Egyptian soldiers and officers help fight Britain's wars. But it was later used in the racist way described above.
I remembered this saying as I was watching pictures of Pakistanis celebrating in the streets following Mr. Musharaf's resignation. I'm sure no Egyptian would now dare use it anymore.
And although I'm strongly against all racial slurs, but I won't be too surprised (may be even not offended) if Indians (who are leading the world in IT services) and Pakistanis (who just toppled their dictator) would start using the slur: "Do you think I'm Egyptian?" to describe the technically & politically challenged!!!!