As part of my duties for the Sloan Digital Sky Survey, I check all the spectra we take which the software is not able to identify. Some times this is because the object we imaged is no longer there. Satelite trails, asteroids, supernovae and comets all fall in this class. A few weeks back I got an email from Mike Solontoi from the University of Washington who was compiling a list of all the comets imaged by the SDSS; so far he had compiled a list of 11 found using 4 different techniques. I only had notes I was able to find on 1 big one I stumbled across recently (older notes were lost in an email crash). To find more I performed a skyserver query to look for galaxy targets whose spectra were unidentified and had very low signal to noise. This provided 5 more, the first four of which were on Mike's list (as was the bright one I had notes on), I'm haven't heard back from him on the 5th, but I'm hoping it's a new one. By that I mean new for him, all 6 on my list turn out to be known comets. You can check out the list here.