Do I need an antenna for GPS Logging?

I’m looking for a GPS logger for Geotagging photos while hiking or traveling. I was looking at the GeoChron Blue and saw a hookup for an antenna on the EM-408 Module. If I’m walking around on city streets or just hiking in the mountains with this thing in my bag, should I have trouble logging data? If so, would an antenna hanging out of my bag help?

You shouldn’t have too much of a problem with the ceramic antenna already mounted on top of the EM408. Like most of the GPS modules, open sky will yield more positive results then a more urban environment or inside.