Seems like everyone loves those reflections. I've wrote an article that helps you make a simple/basic logo reflection. Check it out: http://ryancanfield.com/how-to-make-a-reflective-web-20-logo-with-photoshop/ Hope this helps you all
That's definitely good for beginners but it could get much more complicated for advance users (creating really neat reflections).
when web 2.0 words become very popular, many online logo generators came which included reflections. I used them but i dont know how to in photoshop. I contacted the owner and got the script too.