I ride my mountain bike mostly cross country and mostly by myself. I am also a frequent road rider and do 45 - 65 road miles several times a week with just one or at most two short stops to take a picture or water the bushes.

I do many of my XC mountain bike rides 'kinda like my road rides and don't stop very often, but then I don't ride XC real fast anymore. My normal XC riding style is to "I'll just make this one little climb and see what's up there before I stop... well that was fun so I'll do one more little climb...this downhill is too much fun to stop so...." and what do you know - an hour has gone by with no stops.

The other day I did 23 miles with 4000'+ climbing (based on GPS track and Google Earth) or 2800'+ climbing based just on the GPS display. On that ride I didn't feel so well (had serious flu symptoms the next three days) and was having trouble breathing efficiently so I was stopping a lot more frequently! That new behavior, stopping to view the scenery and catch my breath, led me to start thinking about what is typical riding behavior in hilly XC terrain.

How often, and for how long do you experienced XC riders, in decent shape, stop during 20+ mile rides?
Do you stop every so many minutes/hours or just when you feel like it or when they scenery is spectacular?
Do you stop more when riding in groups?