Mac keyboard

one of the good thing Mac can do, is can type these symbol very easily & directly by keyboard alone: ≤≥≠±÷ ∞™€¢£ (for ≤≥≠÷, the mac’s wonder-script: AppleScript, use them as operators in the programming language) and the most special symbol – i wonder what is the unicode of that 🙂 (browser can’t show, those with mac try: option + shift + K)