I've got some old Agfa folders and a few other cameras that require you to set the focusing distance manually (No direct focusing through the camera viewfinder).
Long distances are pretty easy to configure for hyperfocal focusing, especially with smaller apertures. Close focusing with wide apertures gets tricky - especially if some camera are metric and some imperial (having to remeber which is which). I was looking at getting the optical hotshoe mounted rangefinder, but I would need one of each and besides being pricey, I hear their prone to going out of alignment. Plus the tiny little windows are a pain to use with eye glasses on.
I came across this at Canadian Tire today ($8.99 on sale!) Other may find it handy to for rangefinding.
According to the specs, its good 1-32' (0.3-10m) = or - 0.5%. Has a laser targeter, but is ultrasonic for measuring. The thing is very small (2") and pocketable.
So far, it is accurate for targeting big objects. Not so much for tiny small objects. The measurements are consistant so far. Its easily switchable between metric and imperial.
The stores in Ontario have it on sale this week if you could use it too. Can't argue with the price.
Bharat.