I once passed a nice test in a Psychology course. I had to fill a questioneire (sp?) rating the relevance of all kinds of statements to my personality. Two weeks later, I recieved a preofessional psychological analysis, and was asked to rate the relevance of its statements to my personality. More than 80% of the statements in that analysis matched my character, some strikingly revealing things I didn't expect to be deducable from that lousy form I've sent.
Then I revealed the whole class has recieved the very same personal analysis, which mostly matched everyone's type. Those statements were clipped out of weekly Astrological reports in the papers, and indeed were phrased in such a manner that they would match everyone.

You can try it at home - Rate from 1-5 the relevance of every statement, from every horoscope in any of the papers. It would much by more than 50%, that's for sure.

Needless to say, Astrology is plain bullshit not only because it lacks any scientific basis or consistency, but because it's utterly nonrefutable.