At the moment, I prefer, in this order, the following currencies, rated according to A) likelihood of appreciation against US Dollar, and B) political safety and relative reliability :
1) Singapore Dollar
2) Norwegian Krone
3) Canadian Dollar
4) Australian Dollar
5) South Korean Won
6) Indian Rupee
In theory, one of the strongest currencies now is, and will be later, Brazilian Real. However, their goobermint is in the hands of an outright Marxist and the Real is therefore untrustworthy.
Be advised that, to deal in Rupee, you will need to open a bank account or brokerage account **IN** India. Again, this is entirely legal (but a bit of a pain in the a&&).
Do spread your risk around. Some assets in one ccy, some in another, some in yet a third.
One of the better books for the layman (as opposed to the professional trader) on the subject has the amusing title "Where To Stash Your Cash Legally", written by a chap named Bob Bauman. Former Congressman (not that that is itself any recommendation at all), highly knowledgeable regarding the nuts and bolts and details of shifting assets offshore and/or redenominating them.
FReegards to you!
So when I skim something like this:
http://www.latimes.com/business/la-fi-amateur-currency-trading-20110403,0,588787.story
I get concerned... is that what you mean?