Good advice that I expect will be widely ignored: only invest in what you know.

So-called high yield investments are (almost?) always dressed-up Ponzi schemes. If you "invest" in them then please lick your wounds quietly when they implode. And if you're one of the lucky few who make money on them, don't expect me to admire your investing wisdom, any more than I'd admire the number-picking brilliance of a lottery winner.