This is definitely something fun, recently I noticed some of the contacts on my BBM had some ghost-like avatars that at first appeared like a standard icon but changed to a different image when highlighted. Being the curious guy that i am, I decided to snoop around and I came across a whole bunch of these cool avatars eg Superman, Mario, Spider-man, Wonder-woman, Batman etc. Not only are they fun, they are also simple enough to make as they are just images created with different layers so that they appear hidden until highlighted. Here is a simple enough step to take if you want to make yours.
Open Photo-shop CS4 and then;
Open a new document, say 150pixel by 150pixel and 72 pixel/inch as your resolution
Get your first layer. It will say Background and a lock beside it
right click and click "Layer from background" and then just click ok.
Now right click the layer and choose "Blending Options"
Find "Color Overlay" check the box beside it and Click the word "Color Overlay" to select it.
Set blend mode to multiply, set the color to white, set opacity to 0% and Click Ok
Set the Fill to 0%
Now create a new layer CTRL+SHIFT+N
Type in the word you want to be in the picture make sure the color is White
to edit color, go to "Image" located on on the top menu
after that Choose "Adjustment" then choose "Threshold"
Setting the threshold level to how you want the image to look, you can then turn it into Black and White
when you are finished you need to delete all the black color
Using the Magic wand tool will help remove the Black colors
Once you're done, save the file
To save Click File > Save for Web & Devices
Save it as PNG-24 make sure the transparency is check and matte is white
To save you the trouble of doing all that (i never completed it myself) My buddy Techrevive from ThemesInMotion has made over 200 of them FREE.You can get them HERE or If you need one made for you ASAP, BBMPics (some icons have very strong language. parental guidance suggested.) can get it done for you for just $5 and they promise to deliver within 24 hours.
If you do end of making some we would love to see your creative work....