Short answer - yes it does.
However, when I tried to use it in a DHC-2 (very noisy) with my old LG phone the headset mic overdrove the phone circuitry making me completely unintelligible. From memory I also tested it on the bench at home with a portable intercom, and my voice intelligibility wasn't a lot better.
I suspect that there is either an impedance or level issue between the D50s and the levels that cell phones expect. One of these days I'll find the lead that came with headset and see how it works with the Nokia.
Has anyone got the cell phone interface to work OK?