gistfile1.rb

balsamiq = 'C:/Program Files (x86)/Balsamiq Mockups/Balsamiq Mockups.exe'
mockup_directory = 'C:/Mockups'
output_directory = 'C:/Mockups/Images'

require 'find'
files = Array.new
Find.find(mockup_directory) do |f|
  if /.bmml$/.match(f)
    files << f
  end
end

files.each do |file|
  out_file = File.basename(file, ".bmml")
  full_output_file_path = output_directory + "/" + out_file + ".png"

  system_command = "#{balsamiq} export \"#{file}\" \"#{full_output_file_path}\""
  puts system system_command
end