Before anyone rushes off and starts consolidating, I just want to draw attention to this point:
Privacy
Consolidating your inputs links them together on the blockchain. This wouldn't be any different when you use the same funds in any other transaction, but you should consider this before doing it.
I usually take care to avoid linking certain address clusters together -- particularly those that have or will interface with a KYC service like an exchange. The fee savings of consolidating outputs is great but it's something to keep in mind. Consolidating all the outputs in your wallet at once could link together most of your past wallet activity.