If you aren't using a DVR at home (and you're still watching TV on cable instead of online), simple SMS service Remember to Watch will send you SMS messages 30 minutes before your favorite show comes on.
With our busy lives, it can be difficult to remember when your favorite TV shows are on, even if you're just sitting at home. Instead of setting up complicated alarms or schedules, Remember to Watch provides the TV listings for you, and lets you subscribe to SMS reminders for each one with a simple click. You can subscribe to an episode or all future new episodes, and you can remove subscriptions at any time. It will send you a text message 30 minutes before each episode airs, so you get the alert no matter where you are, and you have time to get your current task finished before kicking back with the Big Bang Theory.
You need to create an account with the site, but it only takes a second, and makes managing your subscriptions really easy. And, other than standard messaging rates, the service is completely free. Hit the link to check it out.