In order to place a real feel on this, students took iPads outside to discover triangles in their world. Students found real triangles which they applied the Pythagorean Theorem to find a third side. We also used estimated measuring tools (hands and shoes) to find the lengths of the legs.
After we found the measurements, students used the Skitch App and paper/pencil to calculate the hypotenuse.
***UPDATE: After three years from the original post above, Mr. Isham took this to another level by having the students find the triangles outside, but returned inside to explain the process for finding the hypotenuse using Explain Everything.
See some student examples here and here.