Here is the spectrum of a laser pointer taken with the spinning spectrometer

And here's the same zoomed in a little

So, according to my spectrometer the laser pointer emits at about 690nm and I've got about 10nm resolution.

When I measured the laser pointer in a more professional machine it turned out that my angle-to-wavelenght conversion is a bit off, though: the real wavelength is 653nm.

The resolution remains at 10nm, however, since that's down to my machine (input slit, optics, DVD as grating, etc). And 10nm isn't all that bad for a homemade machine, I'd say :)