Seeing that there was quite a bit of mixed feelings in the laser jammer thread, I thought about posting my own version of a "laser jammer" - well maybe more of a disguise method. I really don't endorse this and would never do this to my own bike.

But here goes:
1. Go for a lekker long ride on a dirt road. Collect dust from the rear rim:

2. Just add water:

3. Borrow your kid's bottle brush:

4. Dip the bottle brush in the muddy mixture and splash on your number plate:

5. Voila! Home made photoblocker:

EDIT: I forgot to add. Prepare an excuse about some hardcore dirt that you tackled for whenever the coppers stop you.