Are you going to work, being at party or riding a bike? Have you seen something hilarious what amused you to tears? Would you like to remember it for long time?
Your Android homescreen could be a perfect place for such a memory!
Just use your phone, make a video and create a live wallpaper about this event. Now install it and whenever you look at your homescreen it'll remind you of that day :)
Using the phone should no longer be boring but fun!