Cash Management

[Rembert]

I think cash is the best cash management option. Depending on your broker you receive interest for your cash position.
http://www.interactivebrokers.com/en/p.php?f=interest

Of course in this environment where central banks have pushed interest rates close to zero one gets next to nothing. Before 2008 I remember getting similar interest rates as a standard savings account with a bank for my EUR cash position.

One could try and pick the best currency but that's another thing.