Bembo’s Zoo is a book available at Amazon.  But it is also an amazing website that uses flash animation to delight the viewer with animals created from the letters that spell their names.  Visually, it is very appealing, and especially great for use on interactive white boards.  To use it for a learning activity, you might want to try showing it to your students, and then challenging them to create their own animals out of letters.  Extending further, some students might want to draw other objects using letters, or even create their own alphabet book with a different theme – such as inventions.  The app for iDevices, TypeDrawing, could be used for a similar activity.