Yep, got one of those and I found it useless as it simply bends the bar that sticks through the wheel. Only way to get the fecking nut off is with someone (lardy is a good thing in this case) sitting on the bike, pressing the rear brake lever and using a scaffolding bar on the socket.
Mood: Awaiting the arrival of the sun and the disappearance of the rain
Ray,
Possibly cheaper (good old yorkshur trait I know!!:P) and more flexible is the item I use.
It's a 9m retracting tape measure from any hardware outlet. It wedges between the rear brake pedal and the swingarm pivot bolt lug thus locking the back wheel solid (if your rear brake's any good)
Makes getting the rear wheel off much easier and possible with one pair of hands and no bloodloss. Would work the same for the 'other' jobs you mention.