There is, and I know this firsthand because a) I buy things from Amazon.com and b) since I have an Amazon credit card, I also get an occasional Amazon gift certificate from the company as my credit card usage reward. It's not a great deal but it's fun to get a free book or movie now and again!

There are a couple of ways you can take that gift code and apply it to your account, but my favorite is to just start out on the Amazon Gift Card area, which you can find here:

Amazon.com Gift Card Page

Clicked on it and have that page open in another window? Great.

Now look down the left side to find the following set of links labeled "Manage your cards":

As I have highlighted, you'll want to click on "Apply to Your Account".

Now it'll verify you're really who you say you are by asking for your password again:

Once you've verified your Amazon.com identity, the next step is to enter that confusing certificate number...

It's case insensitive, fortunately, so if your gift certificate code is something like "9F3RZ" then "9f3rz" will work just as well.

Enter your certificate number carefully, then click on the yellow "Apply to Your Account" button. If it works properly you'll see something like the following:

Notice on the right your total gift card balance. Mine is $100. Nice. I should go buy something. :-)