Quick example of how to do a geo query with the moped library and convert the output to JSON

places_of_interest.rb

require 'moped'
require 'yajl'

session = Moped::Session.new([ "127.0.0.1:27017" ])
session.use "imminence_development"

query = session.command({
	geoNear: "places",
	near: [ -2.16933984212885, 52.27229461855149 ],
	spherical: false,
	query: { service_slug: "register-offices", data_set_version: 2 },
	num: 5
})

output = query['results'].collect { |row| row['obj']['distance'] = row['dis']; row['obj'] }

# Use YAJL as it's said to be much faster than the core JSON lib
Yajl::Encoder.encode(output)