Yes, it's in the photo info. On a Mac, you can see it by selecting the photo, then hitting command-I (or right clicking and selecting "Show Photo Info." There are two fields near the bottom for "GPS Latitude" and "GPS Longitude."
Note that this also works on the first gen iPhone -- when I launched the camera, it asked whether Camera could use my current location info, then it tagged the photo I took.
However, I don't know yet how to use this data -- as a previous poster said, Flickr doesn't seem to know where that picture came from. When I view the photo in Flickr, the EXIF info still contains fields named "Latitude" and "Longitude" with the same data as shown in iPhoto, but Flickr can't put the photo in the right place on the map.