Had a bit of a close call today.  Thought I'd share, in case you encounter the same thing on the road.

Come down some twisty corners, I was suddenly unable to downshift and the clutch lever lost all resistance.  Stuck in 4th gear, I just braked/coasted to the side of the road and killed the ignition.  I thought the clutch cable had snapped and was resigned to wait for a tow truck, which was going to take hours as I had ridden way into the hills.  Also couldn't roll the bike anywhere, as it was stuck in gear.

To fiddle the time away while waiting, I took off the small clutch adjustment panel on the left side, and to my surprise found that the nut had slipped off.  This allowed the clutch adjustment rod to somehow unscrew itself, which meant the clutch would not disengage.  Screwed the rod back in, then locked it with the nut.  Thankfully this was an easy fix, as I didn't have any hex sockets around to do any more serious work. I was able to ride back home just fine. 

Back at the home garage, decided to add a second nut with some Loctite to hopefully keep this from ever happening again.

So what did I learn?

1.  Knowing how to fiddle on your bike can sometimes get you out of a pickle.
2.  Always carry a small set of tools.  Luckily the above repair only needed some screwdrivers, else I would have been hosed.
3.  Spending hours learning from this forum is definitely not a waste of time at all! 

Awesome of you to share, Endo... great post!!!

And I certainly do agree with all 3 of your points... especially the third one

Always a good feeling when you can get back on the road yourself.

Man, reminds me to sort out a tool kit!

There is an adjustment guide for that nut I followed which explains it all pretty well on the wiki

Yup.... that wiki talked me through things a couple months ago when I fiddled with it.  Thank the motorcycle gods I still had it tucked in my dusty memory banks...

It's not to hard to ride without the clutch.

Upshifts are very easy, just snap the throttle shut and upshift in one motion, the bike will smoothly snick into the next gear. Racers never use the clutch on upshifts.
Downshifts are a bit more difficult, the trick is to coast down until the revs have dropped almost to idle, then give the throttle the barest blip to unload the dogs and downshift. Same procedure for finding neutral.
The harder part is if you're in an urban area and have to deal with red lights. Find neutral as you're coming up to the light. If you have to stop, when the light turns green paddle like crazy with your feet, when you get going a couple of miles per hour just jam it into first.

It helps a lot if you know how transmissions work and why the secret is the moment between acceleration and deceleration when the dogs/slots are unloaded.

I've had a couple of broken clutch cables over the years, no big deal getting the bike home.

Good instructions--I've had to do it myself a few times.

Thanks Rich!  That's graduate level bike riding 

So I didn't have the presence of mind to get it into neutral before I killed the engine. 
I'm familiar with clutchless shifting; just not sure how it works without some RPMs to back you up.

What is one supposed to do if the bike is stuck in 4th gear, the engine is stopped, and the clutch doesn't work?  Any way out of that?  I can't even get my bike to roll in 1st gear on flat ground with the motor off.

With your foot lightly on the shift lever, rock the bike back and forth. Or, with the bike on the center stand, put left hand on shift lever, rock wheel back and forth vigorously, and press down and release shift lever.