How many times have you signed up for a free subscription or been enticed by an “introductory offer” only to be hit with a full-price bill months later? It happened to me recently. I typically only sign up for my XM Radio service when they are offering a deeply discounted rate. They normally charge $20-$30 a month, but when I sign up during a sale I can get six months for the price of one month. Well, my six months were up and I forgot. I didn’t realized until the end of the seventh month when I got a bill. I had forgotten to cancel.

This happens to the best of us and companies know it. Why else would they offer free magazine subscriptions, free subscriptions to websites when you purchase your new gadget or special introductory offers? They know you’ll forget to cancel your subscription in time and they’ll be able to charge you full price.

If you need help remembering to cancel a subscription, try using Remember the Milk. It’s a free online task management system that reminds you via e-mail text or even your Twitter account that there is something you need to accomplish. You can also try setting up Google Calendar. As soon as you sign up for an introductory offer or subscribe to something that needs to be canceled, input it into Google Calendar so you won’t receive any unexpected bills.