Sort photo collection from iphone into folders by year, month and city/region
Answer #1  Requires script writting, exiftool, and the creation of a places database.

A partial answer would use a script and exif tool.

Exiftool can read both the exif and IPTC as well as most other metadata in an image.  Geolocation is part of the data it can read.

So if your photostream is in folder ~/PhotoStream  (I've no idea where you keep it.)

foreach photo in ~/Photostream {
  (year,month,lat,long) = exiftool {bunch of flags} photo
  foreach placename in ~/Placenames {
    # Place name has lat, long, name, radius
    # Calculate angular distance from present lat/long to each placename
    distance = sqrt((picture_lat - place_lat)^2 + (picture_long - place_long)^2)
    if (distance &lt; place_radius) { # found one!
      if not exists directory year-month-placename {mkdir MyPics/year-month-placename
      move file year-month-placename
    }
}


The problem with general sorting for geographical data is that it is intrinsically two dimensional.  If you sort just by lat, you end up with New York City being adjacent to Rome.  

The script above while not enormously difficult will take some time to get working right, mostly due to the place names.

Answer #2 Sort into folders by date, and add places manually.

I would suggest that unless your place names are fine enough grained that they change multiple times in a day.  (E.g. you have separate entries for your hotel, the temples, the coliseum...) that doing a first bin by date, then rename the resulting folders manually.

I recently went through my aperture file (15000 images) and essentially did this by hand.  Few of these pics have geolocation info.

A:  Renamed each image in the format yyyy-mm-dd hh-mm-ss.  Aperture can do this automatically.

B:  Make a batch of year folders. Made a project in each one called 'unsorted'

c:  Manually moved each year's pix into year folders/unsorted.

d: Make a batch of month projects in each year folder.

e: Move the pix from unsorted into appropriate month folder.

f: In some cases I would make a special project yyyy-mm-project_name where I had a large number of photos dealing with a single topic.

This didn't take as long as it sounds.  

Much longer was going through each folder and applying keywords.  Well worth doing.