I think this is such a great idea. Happiness in a jar. I saw this on Google+ (see link below - I can't seem to insert link properly when writing on the Galaxy Tab). Write down a good event and keep piece of paper in a jar to review at end of the year.
https://plus.google.com/110614416163543421878/posts/g85tcfys221 or here https://plus.google.com/115337148988005892196/posts/jTmgrCcSjyv