The premise that got me started is that I don't do anything fancy -- just do it everyday, along with my meditation and pranayama practice. These are routines that are equivalent to office yoga -- stuff that you can do to relieve tension from sitting at a desk all day.

• The upper torso part of Cow Face pose or Gomukhasana -- I have to use a strap to reach between my hands.
• I do a simple pectoral stretch, usually pressing my arm against the wall, and the reverse that by pulling an arm across my chest.
• The clasped hands behind the back of prasarita padottanasana (wide-legged standing forward bend). I do this several times a day, loosening my shoulders and forcing my hands down as far as they will go and then lifting my arms out away from my body. This has done wonders for my mobility of my shoulder blades.

I've found two good books with shoulder routines: Erich Schiffmann also has eight shoulder stretches, some with a strap, in his book Yoga The Spirit And Practice Of Moving Into Stillness. I can do only five of them. Miriam Austin in Cool Yoga Tricks has a whole section on loosening up the shoulders.

I still can't do the top half of Garudasana or Eagle pose. My arms and hands simply will not intertwine.

Postscript: here are some other ideas for office yoga: the University of Alberta has some detailed instruction with drawings in Word format. Easy Desktop Yoga has a free video download. Cyndi Lee gives advice in Yoga Journal. And then you have My Daily Yoga, which has some fun graphics.