If you want to put logos or pictures on the silkscreen of a board, here's a methodology for doing it.
I assume you're using PCB as your layout tool.

Steps:
1. Open your logo with gimp (gnu image manipulation program).
2. Resize the image using the crop/scale tools.
3. Threshold the image to black and white only.
4. Save image as a ".ppm" image, and use "raw" as the format.
5. save the rawimg_to_silk.c and compile it (gcc -o rawimg_to_silk rawimg_to_silk.c).
6. run "./rawimg_to_silk .ppm > " (ie: ./rawimg_to_silk frog.ppm 400 > frog.fp)
7. In PCB use the "file->Load Element Data to Paste Buffer" option and select
8. Click to place your graphic.