Don't get the bike serviced/tuned
just before your trip - if they FUBAR something you need to give them time to rectify it. Nothing worse than starting a long ride with a bike that's not all there.
I limit my roadside repairs to simple stuff like tyre pressures, bulb replacement and chain lube. So a small/simple and light tool kit and AAA membership for peace of mind. I'm not going to repair flats so I don't bother with puncture repair kits.
I have the stock seat and yes, it's a bug*er long distance but I haven't bothered with a windshield - I hate the buffeting. Yes - get throwover panniers and a tank bag or a duffel like Frank's. You want to be able to quickly unclip them and take them with you at stops where you can't see your bike and get to it PDQ. Anything that takes more than 15/30 seconds to mount/dismount is a PITA. I cable-tied the clips that attach to the bike so I didn't have to worry about them getting lost.
In addition to Frank's list:
Tyre pressure gauge - a good one.
Cable ties
Ziplock baggies
Water/juice boxes (you dehydrate a lot quicker on a bike or so I find)
Snack bars.
Small digital camera (and optionally, a handle bar mount if it takes video clips - great fun! See example
here)
If you are in doubt about whether to take something, I would say don't. Travelling light is easier, more relaxing and there are Walmarts everywhere.
If you don't do anything else, lube the chain and check the tyres everyday or twice daily, depending on mileage.
Oh yes, and have fun.
[ This message was edited by: parrycm on 2005-12-06 17:56 ]