Nerds have junk boxes. They used to be filled with bits and pieces having mainly to do with short-wave radio. Now they tend to contain computer stuff like old memory chips and pc cards from 20 years ago.

Today our VoIP phone was switched from another provider. It only had one line instead of the previous two. We have old analogue phones strung through the house that work fine with the ATA, but I was suddenly confronted with the problem of connecting them all to a single port. I went rummaging and found plenty of old phone cables with RJ11 plugs, but nothing in the way of doublers to link the additional phones. Do they even still make those? 

What I did have was a box full of dial-up modem cards. I have been trying to get rid of them for years, but no-one wants them. I took a look and found some with the usual double phone/line jacks. These were easy to unsolder and remove. I took one of the phone cables with plug and cut off a bit. I soldered it to the modem connector, wiring the two jacks together, and plugged it into the ATA. Works perfectly.

Moral of this story: Never, ever, ever throw anything away. You never know when you may need a dial-up modem to connect your phones.