Wearable GPS Antenna
I too thought whats wrong with a normal Antenna, but the answer is the problem is the human body.  

There are manufacturers that make "fabric" antennas, but these tend to be Mil-Spec so are going to cost a fortune.  (http://www.pharad.com/gps-wearable-antenna.html)

I found this site that explains what the effect of the body is, and seems to make their own antenna.  http://www.pharad.com/gps-wearable-antenna.html

I think you might be better off looking for a high gain antenna and the choice of active or passive will probably be based on the interference you get from the body.