Technically, no - You have 90 days per year in the EU. However, they usually don't notice if you leave the EU for a few days and come back, at least by every account I've heard. I have a friend who's currently "resetting" her EU stay every few months while she's living with her boyfriend there - hasn't run into trouble yet.
This isn't to say that it's legal, but it seems to be pretty overlooked. Of course, I'm sure how often they overlook it is based upon the country that issued your passport. That probably determines if you're some sort of 'social welfare' threat...