Jenny: I have to agree with regards to the MoJavi bags. We have been using them for rallies since a few years ago and they have really made riding and racing easier! I tried using a backpack again during a ride a while back and I hated it! Heavy and sweaty! They are perfect for rallies as they contain all you need and more and never get in the way. Highly recommended!
Oh, and did I mention that we are Giant Loop retailers..? (But only because they make awesome bags that actually improve your bike instead of the usual opposite)