Several years ago, I was working with a bride and her mother.  Her mother had the guest list database on her office computer.  She was having difficulty merging the database to create place cards, so she e-mailed the whole database to me.  I had the same difficulty, but kept the database on my computer. She called me three days later, in tears, saying that I was her last hope. Her computer had crashed, and she lost the database. All the names, addresses, responses …gone!  Fortunately, I still had the database and was able to send it to her home computer.  I had coached her several times to print out the database, so she could work on it at home, as well, but she is a computer person and doesn’t like paper. But from that point on, she printed out the database and took it with her everywhere!  Lesson - always have a hard copy of your invite list and take it with you.