Oh yeah -- I wuz going to post a photo of our El Cheapo tiller lock. Here it is: simply a notched piece of plastic loosely screwed at the front and tightened by a knob at the rear. Thru the V notch runs a grippy length of 1/4" line that is tied to the stern cleats. Ta da.
I use more or less the same setup, except I splurged the 20 bucks for the mass-produced version
. (Don't bother. Bob's probably works better and is certainly more durable.)
I have never sailed any other way than single hand, so that little guy has been pretty necessary for me. In fact, I was just thinking today that I may have developed some bad habits as far as letting go of the tiller while tacking is concerned. Do you guys worry about that?