The land idea is a good one, a friend of mine has just bought some in the Cayman Islands.
Alternatively, you could look at buying houses/apartments off plan in Europe. My aunt bought three houses off plan for £20k each, and sold them for £45k each.
Also Luke, you could go into stocks and shares. But as already mentioned, the market is volatile at the moment. Which can be a good thing, especially with AIM shares. I lost around £1k in Oil stocks earlier this year, only to have an oil strike confirmed 1 month later. So not only did I lose £1k, I also missed out on around £10k profit if I would have held. I guess when Warren Buffet said that the stock exchange allows money to be transferred from the impatient, to the patient, he was correct! I promised myself to stay away from Oil unless I have a large amount of money that I could lose without worrying myself. But you don't just have to look into Oil. I had stocks in a company called BLNX, which I bought at 24p, and recently sold out for 83p, and these are still rising.