Geocoding Changes

def geocode_address
  geo=Geokit::Geocoders::MultiGeocoder.geocode (address)
  errors.add(:address, "Could not Geocode address") if !geo.success
  self.lat, self.lng = geo.lat,geo.lng if geo.success
end


That's an ugly method. 5 things that are wrong with it:
1. Use unless geo.success instead of [if !]
2. No need for the two if statements. Should be
self.lat, self.lng = geo.lat, geo.lng if geo.success
3. Use self during assignment when referring to attributes
4. Indentation is dumb and wrong
5. I'm not sure if I missed it or covered it in problems 1-4/

According to geokit-rails README

acts_as_mappable :auto_geocode=>{:field=>:address, :error_message=>'Could not geocode address'}

is equivalent to

acts_as_mappable
before_validation_on_create :geocode_address

So, if we want the location to be updated everytime a talk's location is changed, as is currently expressed in the before_save
before_save :geocode_location, :if => proc {|talk| talk.location_changed?}

we can simply do the following instead

in Talk.rb
acts_as_mappable
before_validation :geocode_location, :if => proc {|talk| talk.location_changed? }
include GeoKit::Geocoders

then the method becomes:
private

def geocode_location
  loc = MultiGeocoder.geocode(self.location)
  self.lat, self.lng = loc.lat, loc.lng if loc.success
end

All the tests still pass this way and it cleans up the code quite a bit.

Because this method (geocode_location) is used in Talk.rb, Speaker.rb, and Event.rb, it might be beneficial to pull this information into a module and include it where needed, to help keep the code DRY