thanks for the comments.
Actually, I quite like this robber fly as I seldom see it. Its a very interesting insect. Here are some info:
"Robber flies are not to be trifled with. Capable of immobilizing bees, wasps and other insects larger than itself, robberflies catch their prey in mid air. As with other aerial predators, robberflies have excellent vision, characterized by two conspicuous compound eyes. The mouthparts of this family have been modified to a stabbing proboscis. Flies were revered by the ancient Egyptians who awarded a military honor in the form of a golden fly pendant."
http://www.bugbios.com/entophiles/diptera/dipt_004.html