You've probably seen this effect all over. It's pretty simple to do, which is why so many people use it.
Start off with a plain black-and-white image, white text, black background. The text should probably be bold, sans-serif. Now, rotate the text 90° counter clockwise. Add Wind (Filter/Stylize/Wind) then rotate back. Now blur the image (Filter/Blur/Gaussian Blur) with a radius of about 2.5 pixels. Now ripple the image (Filter/Distort/Ripple). The only thing you need to do now is colorize the image. There are two ways to do this. One way is to convert the image to greyscale, then convert to Indexed Color. Once you have converted to Indexed Color, go to Color Table and choose the Black Body table.
The second way to do this is to adjust the image's Hue/Saturation by hand, which can be time-consuming but often produces better results.