Face Collage Maker is a tool used for converting this
to this
Create a directory “facecollage”under C drive. Then create the following sub directories:
->source
->collage
Now copy your face image to facecollage directory and change the file name as main.jpg.
Copy a number of images to the source directory.
Now you show have some thing like this:
c->facecollage->source->a number of images
c->facecollage->collage
c->facecollage->main.jpg
Finally, download face collage maker 
and double click it to run. After two minutes(depends on your hardware), you should be able to get a collage face under c->facecollage->collage.
This face collage maker is in an initial version. I would appreciate it if you let me know there is any problem, so I can improve it.
Updated: Face Collage Maker 2.0 Download link.
nice software