A new patent application revealed this week may give clues to what Apple is planning to unveil with its rumored tablet computer.

According to AppleInsider, Apple’s fabled tablet computer may employ a dynamic surface that gives users tactile feedback when typing in order to identify individual keys. One anonymous source told The New York Times that tablet users would be “surprised” at how they interacted with the device, and the new patent application would seem to be indicative of this.

Using what’s called an “articulating frame,” the surface of the tablet device would create physical bumps or dots for the user to feel when it is in keyboard mode. Such surface features would retract and disappear when the device is not being used to type. The new patent application, entitled “Keystroke Tactility Arrangement on a Smooth Touch Surface,” is similar to an earlier application first filed in 2007.

“The articulating frame may provide key edge ridges that define the boundaries of the key regions or may provide tactile feedback mechanisms within the key regions,” the application reads. “The articulating frame may also be configured to cause concave depressions similar to mechanical key caps in the surface.”

According to the patent application, such a system would intelligently determine when the user wishes to type and when they intend to use the screen as a pointing device. Such technology, while likely aimed at the tablet rumored to be announced as early as January 26th, could also be ported to the iPhone and iPod touch as well.

AppleInsider points out that Apple has been rumored to be working on a tablet computer for many years, and such a device has been the number one focus for CEO Steve Jobs since returning from his medical leave this summer.