I converted the GNS data for Niger into a gpx file. It contains over 31000 POIs for Niger, mostly names of settlements, but also administrative stuff (district names etc).

osm.wiki/GNS

It can be used as an overlay for your JOSM session. It can be downloaded at:

http://www.flusslinie.de/nigergnspois.gpx

I decided against adirect import, first because it is way beyond my skills ATM, and second it also has a lot of inaccurate and too old data in it.

The overlay gives you an idea where some villages and towns are and how they are called. Together with the Yahoo and Landsat imagery one can pinpoint the exact location, the name of the settlement and roughly estimate the size (village/town?) of it. Also it gives you a hint about where to look for the roads in the satelite imagery.

Only recently, I see at least some new roads emerging on the slippy map. This is great news - thanks to all contributors.

Christian