When I looked at the batch of fansigns made by mailman's girls they didn't look bad but it all looks so amateur like. A message written on a piece of cardboard looks a bit crappy and unprofessional.
Most webmasters use fansigns to promote the girls in question through their websites and in most cases a url for the site is requested.
Now for the part how to improve the cardboard messages to something that will catch the eye of the surfer.
Very simple, instead of a message on a cardboard, put the girl in question next to a computer in a sexy pose, type in the url of the site in question and there you have it. I think this will appeal more to the surfer than some handwritten message or a computer generated message.
To go a step further, use a laptop and the girl can pose in a more creative way based on the same system.
To go extreme, hook a pc to a plasma screen, put the site in question on it and have the girl pose in front of the screen.
That would be way more spectacular and would have several advantages.
The girls or the person that writes all those signs should not spend hours writing down all those messages.
The fansigns would be way more attractive to the surfer, again benefits for everybody.
Shooting 100 or more fansigns would take only 10 minutes in total.
The surfer will go "ow look it's xxx and she's on the same site as me"
*The only thing to look out for is that the pc screen shows up fine in the pictures.