This video is a clip of a young man who holds the record for reciting 22,514 digits of Pi visiting with David Letterman. He is an autistic savant, and he discussed with David Letterman how it took 5 hours and 9 minutes to recite all of the digits. He really does an amazing job on the interview, and while he does not recite digits of pi, he gave interesting information on how his brain works different from most others. High school students might find it pretty fascinating.
At my school we hold Pi Day Contests where students sign up to recite as many digits of pi as they can. We've had students recite over 150 digits! The winner wins a real pie, and the runners up earn a "Little Debbie" pie. We sing Pi songs, and we write "Pi-ku" poetry. Other Pi 3.14 Poems are made with the first line consisting of 3 words, a second line with one word, and the final line made up of 4 words, all describing pi. Teach Pi , and The Joy of Pi have lots of ideas to use in your classroom as well....and we can't forget Pi Diddy! (see youtube below)