I have been buying Lego sets and holding them until the prices start to rise. I think that during the holidays, you could picks up a few sets on sale and put them away for a little while. They usually take about 2 years, so it is a buy and hold strategy, but it is well worth it. Just let me know if you have had any other ideas on good buy and hold items that gain value exponentially .
http://www.telegraph.co.uk/investing/shares/lego-a-better-investment-than-shares-and-gold/