Which is the best tool to monitor replication on MySQL 5.5.20? I have just installed and setup replication for 3 MySQL 5.5.20 server( 1 Master/ 2 slaves). I intend to add more slaves to the equation. 

Which is the best software tool to monitor the replication status ( like SHOW SLAVE STATUS \G;)

Also i want to know, how much is the replication lagging in time and error reports if there is any error in replication. 

Thanks in advance
Checkout Percona toolkit. Look at pt-heartbeat, and some of their other tools as well.