Measurement OF Ds+ -> l+ nu and the Decay Constant fDs

I report preliminary CLEO-c results on purely leptonic decays of the Ds using 195/pb of data at 4.170 GeV. We measure fDs = 280.1 +/- 11.6 +/- 6.0 MeV, and fDs/fD+ = 1.26 +/- 0.11 +/- 0.03.