This example is made using the lyrics from Jingle Bells which I found by searching using Google. I then used http://www.wordle.net/ and pasted in the lyrics.
Just a few handy tips, if you you want two words to stay together such as ice cream use the ~. Eg. Ice~cream. If you want to remove a word from the wordle you can right click the word to remove it.
To take this idea a step further you can use http://www.tagxedo.com/ . This site allows you to make word clouds into a shape. Here I used Jingle Bells lyrics into a heart shape and O Christmas Tree into the shape of a Christmas tree.
Next, to add some more Christmas cheer you can use http://www.picnik.com/ . This site allows you to edit and add to your images. It offers some great text, graphics and frames for Christmas. Once you have finished you can save your final image straight to your computer. Here are my finished products.
You could print out your images and paste them onto blank cards or laminate them and place a magnet on the back to stick it onto the fridge. Of course this process can be adapted into any other theme or activity.