Okay, I couldn't remember the name of this stuff while at work, but I'm home now and looked in the cabinet.

If I am going to be doing a number of long, hard rides close together, I will make sure to drink Endurox at the end of each ride. I honestly think it helps in recovery. I am less tired and/or sore the next day. I don't drink it while riding - don't think I could choke it down and it's really meant to be a post-ride drink. I keep the amount I need with me in a zip-lok bag, fill one bottle with water, shake well, and drink it down immediately after finishing riding. I am sure there is a combination of food and drink that would work as well, but this is so simple and readily available. I don't use it after every ride, just the ones that take a lot out of you.

The companion to Endurox, meant to be used while riding, is Accelerade. The flavor/texture leaves something to be desired but I can manage to drink it. Again, I don't use it for most rides, just those that I know will be long or intense. Then I'll do one bottle of Accelerade to one bottle of Gatorade. That combo, plus Gu's as needed have gotten me through many a fast-paced century ride and even one double century (with some real food thrown in!) The stuff isn't cheap, but often you can find it for sale at Performance or Nashbar or any of the big bike online stores. I think GNC has a generic version that works, also.

Off-topic answer to question:
ragbrai 40, yes, I am going on RAGBRAI this year, but not the whole thing. I'm riding out to the start and then doing the first three days. Do you go with a group/team/ club?