Currents in the Air, Ocean, and Lakes

These have been around, but always awesome!

• NOAA WeatherView
• Windyty (global wind and weather forecasting)
• Wind: USA 
• Global Wind, Temperature, and more (click on earth in lower left to select your overlay - including the Misery Index)
• Ocean Currents (USA)
• Ocean Currents (Global)
• Great Lakes Currents
• Tokyo Winds

Here's Esri's version of the global wind map on GitHub.