I bought a battery powered cell phone charger yesterday for the household emergency kit. Since my mother and I both have Samsung handsets, I bought the "fits most Samsung phones" model after a quick look at the plug to make sure it was the right size and shape. I did not actually plug the charger into my phone, I just measured the slot against the connector.
This morning I tried to actually plug the charger into my handset. It would not fit. It looked like it should go in, but the connectors wouldn't mate. However, it does work with my mother's handset.
The reason I find this strange is the electric chargers appear to be identical and are interchangeable between handsets.
So at least now my mother has backup power for her cell phone if the power goes out. I suppose I'll have to do some more hunting to find one for myself.