Double Encrypting with two different keys
I don't think it's a bad idea - neither does Bruce Schneier.  In his book Applied Cryptography, there is a section called &quot;Cascading Multiple Block Algorithms&quot;. He basically states that provided that two distinct algorithms and two independent keys are used, then the result should be at least as difficult to break as the strongest algorithm.

If Alice and Bob do not trust each other’s algorithms, they can use a cascade. If these are stream algorithms, the order doesn’t matter. If they are block algorithms, Alice can first use Algorithm A and then use Algorithm B. Bob, who trusts Algorithm B more, can use Algorithm B followed by Algorithm A. They might even add a good stream cipher between the two algorithms; it can’t hurt and could very well increase security.
Remember that the keys for each algorithm in the cascade must be independent. If Algorithm A has a 64-bit key and Algorithm B has a 128-bit key, then the resultant cascade must have a 192-bit key. If you don’t use independent keys, then the pessimists are much more likely to be right.