venues:
id,remote_id,drivetime

events
id,venue_id

class Event < ActiveRecord::Base

  acts_as_line

  attr_accessor :venue

  def venue
    Venue.find(:first, :conditions => {:remote_id => venue_id})
  end

  def self.drivetime(i)
    find_by_sql "SELECT * FROM events WHERE events.venue_id IN
                 (SELECT (events.venue_id) FROM venues
                 INNER JOIN events ON events.venue_id=venues.remote_id
                 WHERE venues.drivetime <= #{i})"
  end

end