Just a thought about playing around with interest rates. I.e. If your able to secure a loan (possibly a large loan?) for an interest rate less than the highest long term term deposit and use the loan to fund the term deposit then the result would be a risk free profit with no capital outlay?
This was just a fleeting thought and is highly likely to fundamentaly flawed in someway, although on very quick investigation I can't see exactly why it wont work.
So the main issue would be the loan, granted a home loan is for a home, although its not like the loan money is being squandered irresponsibly, its being invested and that would help sway the granting of any loan. Therefore im assuming/guessing that there would be investment loans (preferably as large as possible) that could be secured for an interest rate less than about 8% ? 8% is the highest long term term deposit i've seen around. If the investment loan can be obtained for under that amount then the difference is risk free profit with no initial capital required.
So please poke holes in this theory if they are obvious.