Pool_stats is a project mainly written in Ruby, it's free.
Most Bitcoin mining pools provide an API to access their statistics. This allows you to access the stats from many pools with the same API.
gem install pool_stats
http://rdoc.info/gems/pool_stats
Continuous Integration
require 'pool_stats'
puts PoolStats::Bitpit.hash_rate puts PoolStats::Bitpit.round puts PoolStats::Bitpit.shares puts PoolStats::Bitpit.duration puts PoolStats::Bitpit.round_start puts PoolStats::Bitpit.pps_price