Short circuit test on long coaxial cables
Writing up my comment as an answer, incorporating Brian Drummond's excellent improvement upon the concept.


Take an unused 50 meter length of coaxial cable, or somewhat more or less, depending on what you have handy. Even if it is still in a roll, that will work if you can reach both ends of the cable.
Strip a few inches off each end of the cable, pull the shielding braid to one side and twist it, and if you want to be a perfectionist, use some soldering flux and solder the twisted braid end. The result should look like this:
 From Wikipedia
At one end, solder the shielding braid to the central core wire - or just twist them together for a firm connection. 
At the other end, apply your normal 5-Volt multimeter in resistance measurement mode between the braid and the core wire. The resistance you read will give you an estimate of how much resistance the typical cables in use should have, shield-to-core, for a given length.
Let's say that number is 10 ohms for 50 meters (per Brian Drummond's example).
Now, take a few coaxial female connectors like this one:

On the first, use a bit of copper wire to short-circuit the shield tab and the central core tab, at the back of (or inside) the connector's metal housing. That's your zero-ohm connector.
On the second connector, use a 47-Ohm resistor instead of the copper wire, same process: connect the core tab to shield tab using the resistor.
For the next few connectors depending on how many houses you have to identify cables for, use 100 Ohms, 150 Ohms, 220 Ohms, 270 Ohms, 330 Ohms, and so on (standard resistor values about 50 Ohms apart each).
Visit each house, take their cable off the set top box or TV, and plug it into one of the connectors you've modified above. Keep a note of which resistance went to which house. 
Back on the roof, measure the resistance between central core wire and shielding, for each of the cables, using your multimeter. 
The cable with the least resistance (say anywhere from 5-20 Ohms) will correspond to the zero-Ohm connector. Cable indicating 47+x Ohms (say 55 to 70 Ohms) has the second connector, 110 to 120 Ohms has the third connector, and so on. 
With the suggested resistor values, you won't really have to worry about different cable lengths, because the margins are big enough to allow for a 5 to 30 Ohm difference in cable resistance, which should suffice for a wide range of cable lengths. 


Summary: 

In one measurement session, you will have identified the cables belonging to all the houses, from the roof distribution unit. You can thank Brain Drummond for the walking and stair-climbing effort you saved.