My father uses a phone book for his phone. It's basically taped to the back of the phone. When he needs to call my mother, he mutters "now what's Barbara's number again?" Then flips the phone over, locates the number he wrote on a sticky pad taped to the back, then laboriously types in the first few numbers, flips over the phone, then continues to type in more numbers in the same way until he's entered the full phone number.

First time it happened was in a shopping mall in front of McDonalds. A whole bunch of schoolgirls stopped talking to watch the performance. Super embarrassing!