Made in PSP7, extrememly simple, and extremely translateable. Involves Adjusment Layers and Raster Layers.
1. Take your base, crop it to 100x100 (I did 98x98 because I wanted to add a border to it, but you don't have to.)
2. Duplicate your base and set it to Screen at 100%. If it looks a little bright, don't worry about it, it gets better.
3. Make a new Raster layer and set it to exclusion, then flood fill it with #000080 at 36% opacity.
4. Make a new raster layer and set it to (color) burn. Flood fill it with #40FFFF at 100%.
5. Duplicate your base and drag it to the top, set it to softlight at 30%.
6. Go to Layers>>New Adjustment Layer>>Hue/Saturation/Lightness and set the Saturation to 10.
7. Make a new raster layer. Flood fill it with #000080 and set it to exclusion at 15%.
And voila! You're done :) If your image looks a little to bright, you can go back and lower the opacity of that first screen layer in step two. Feel free to add brushes or text, I added some text.
Other examples made by this tutorial: