In a light rain I just put on my windbreaker and keep going. A little wetness evaporates quickly.

In a real rain:

• Head - Waterproof helmet cover. It doesn't have flaps in back to protect my neck, but that doesn't seem to matter.
• Body - Goretex jacket with zip-off hood. Remove hood on bike, reattach in camp. Pit zips wide open on bike.
• Legs - Goretex rain pants (tall size from Nashbar)
• Hands - Winter gloves. They're more like ski gloves but they keep my hands warm and dry.
• Feet - Waterproof covers from MEC. They allow me to use my regular, size-14 shoes.