Buying Dollars

With the exchange rate dropping (hopefully this is G8 related?) has anyone used any of the currency broker companies like XE/HIFX or Moneycorp to move their currency or is planning to this year?

I have been exchanging chunks here and there all summer (and it is starting to drop quite a bit) but the larger amount I need to change I am uncomfortable carrying it over and not having an account to put it in, would dearly appreciate any feedback or advice.

Thanks