You know those windows signs that scroll words with the LED lights in them? Why not have one in your pocket? XDA member xiaojin1985 created a neat app that lets you take a phrase or a picture and turn it into LEDs. So you can write out a message to that car tailgating you in real time.

You can control the speed, color, size of the LED dots and of course, what it says. In fact, you can even take a bitmap (.bmp) pic and drop it into the folder on your phone and it will turn the picture into an LED image. Take a look at the pic of the Fuze (that's the drink) that it turned into an LED image.

This is just an .exe so there's no installation so you just copy the folder onto your phone and run the .exe file from your phone to start it up.

There's a picture in the XDA posting on where to press the screen to control the app with your finger (by the way, press and hold it for a second to get to the settings - just pressing will exit the app).

Simple to use, very neat and fun. Very well written in fact. This is really a good toy.