Living in a very liberal area is a very good source of free comedy. The problem is that there are a lot of protests, but they are "preaching to the choir". A good example is the protest marches. There can be big groups chanting, waving signs marching down the middle of campus. The only hitch is when they reach the edge of campus the group turns around and marches the other way. (Can't be late for class.) That big of a group changing directions is funny to watch. It's like when in small towns the parade will double back for and second trip down main street and all floats have to turn around. I guess as long as the media is there covering it, that's how the message gets out.
The times that messages don't make it outside is a little spot called "the Free Speech area". It is a small amphitheater next to the area to eat lunch...ahh, captive audience. In reality there is usually someone there yelling about something and it provides good entertainment to anyone eating lunch outside. Again more just wasting energy rather then changing minds.
One thing I have found useful is the display of information. Studying human computer interaction involves a lot of displaying information in an easy to digest matter and some protesters have mastered this. For one protest against the Iraq war they used the small construction flags usually used to mark underground pipes. A flag for everyone that has died- so 50,000 white flags covering most of the green areas of campus and 3,000 red flags for the US soldiers that died in one small patch of grass. It was easy to see the disparity and why one group would be mad at the other.
The other display I liked was a chalk drawing on the road. As I rode my bike in onto campus there was a large red stripe drawn on the ground. As I went further it was joined by other stripes and at the very end, the punch-line, it labeled all bars in the bar graph as the national budget with of course the longest being the defense budget. It was just smart to have it facing the way it was so people arriving on campus would receive the impact.