One place to park dollars but tie them to foreign currencies are the foreign exchage traded funds like FXE, FXA etc. These funds trade at exactly the exchange rate times 100.
FXE is in euros and is currently trading at $136.89 and the exchange rate is 136.9/100 euros. Been in and out a couple of times, liquidity does not seem to be a problem. The fund holds euro denominated bonds and makes money on the interest. The stock price is tied directly to the exchange rate.