what is a good no weight/weight room upper body workout

Below is a simple strength training session that I designed specifically for runners, but it's suitable for triathletes too.  All that's needed are some dumbells and a stability ball.  It can be performed in about 30 minutes, hits muscles used for movement within the frontal and transverse planes (neglected by running), plus strengthens the core.  It does all this without overly fatiguing the primary running muscles, so it won't compromise the quality of the next run training session.

Notes: For the exercises that use weights: If you can perform 3 sets of 15 reps with PERFECT FORM, then increase the weight and decrease the reps the next time you do this workout.

Alternate exercise #'s 1 & 2, without any rest for a total of 2-4 sets of each:
1. Side Lunges (Alternating Sides) - body weight x 12-15 reps each leg - http://www.youtube.com/watch?v=FUX6Pz8vV0s
2. Dumbbell Wood Chops - 112-15 reps each side - http://www.youtube.com/watch?v=GuiEZWIHWrA

Alternate exercise #'s 3 & 4, without any rest for a total of 2-4 sets of each:
3. Bent Over Dumbbell Rows - 12-15 reps - http://www.youtube.com/watch?v=eHIpkMAUyiQ
4. Stability Ball Push Ups - Reps determined by ability (stop 2-3 short of failure on first set & try to hold same reps for remaining sets) - http://www.youtube.com/watch?v=r6e8DCFTwj4

Alternate exercise #'s 5 & 6, without any rest for a total of 2-4 sets of each:
5. Saxon Bends (With weight plate, dumbbell, or medicine ball) - 12-15 reps each side - http://www.youtube.com/watch?v=ZCl_uYW8fcQ
6. Dynamic Planks - 30-90 Seconds - http://www.youtube.com/watch?v=UImbPqGzJP4

I have a push up and pull up routine that has been providing me with good results.  I do 5 sets of pull ups with 5 sets of push ups in between the sets of pull ups.  Looks like this:

Wide grip pull ups then wide hand push ups

Shoulder width underhand pull ups then standard width push ups

Hands touching narrow overhand pull ups then decline stability ball push ups

Narrow underhand pull ups then hands touching push ups

Standard width over hand pull ups then standard push ups

About a minute between the sets

I repeat this twice.  I use a chair to help with the pull ups to get extra reps.  Been at this for about a month and can do more pull ups now than ever in my life.  I have no weight training background and developed this plan on my own, take it for what it is worth. 

This year I started incorporating more 'body weight' exercises into my routine. Ones I do include push ups, pull ups, dips, mountain climbers, inch worm, jump squats, wall sits (to name a few). I found a list on-line but in a quick search I couldn't find it. At one point this summer, I was using the playground equipment/area while my kids were at swim practice and they said I looked like I was training for the next American Ninja Warrior! LOL!

Anyway, I a mixed routine of these types of workouts once a week during a kickboxing session (in my basement). I got a standup kickboxing unit a few years ago and it's still fun just to go at it!

I still like doing weights at the gym, but mixing it up has also been fun and challenging. I would love to do Insanity/P90X but don't have the desire to spend the money, so that is where this stemmed from for me.

When I add up your primary question's constraints, it seems obvious ....pull ups.

I feel no other single exercise is as effective nor efficient at improving overall upper body strength, utility and asthetics.

To round out the muscle groups, add in pushups,

then something to engage the deltoid more, might need some dumbells there.