Propaganda is any material (usually a printed flyer) created by a member of the VTLUUG to raise awareness about matters that are important, mainly spreading the use of linux/unix and other free software.
Creating good propaganda
Good propaganda should catch your eye, use vibrant colors and solid imagery. If you're making a flyer, then it's going to be next to around 20 others on a billboard; make it impossible to ignore amongst the sea of other flyers.
The second aspect of good propaganda is to get it to stick in peoples heads, the easiest (therefore best) way to do this is by being funny; however catching people off guard also works really well. Disguise your flyer as something else, only reveal the fact that it's trying to get you to switch to linux at the end.