It may be a big problem for you to always check the PNR status if you have a waitlisted or RAC ticket. Although PNR checking services are available at the cost of just one SMS, but you have to query them all the time.
Don't you think it would be better if an automated service will ckeck your PNR for you and notify you whenever it's status changes. Yes, there is one service freely available for this task.
Mail2Mobi.com provides automatic PNR status update alerts via SMS. You have to put the PNR number of your railway ticket on the website and they will start tracking it. You can put there two mobile numbers.
Whenever the status of your PNR will change, they will send you a SMS with latest position of each passenger. Their services are at best one can expect, even it is free.
How to add PNR for monitoring?
You can login using Facebook Connect option or login directly with your user id if have an account there. This is only to protect the misuse of the site and to be safe from spammers. Sign up here.
Login to your account and go to 'PNR Monitoring' tab.
Put the PNR number of your railway ticket in the box provide. You can also add extra mobile numbers there. SMS will also be sent to additional mobiles. Now click on Add PNR button.
You will get a SMS each time when the status of your PNR number will change.