A list of papers which either use or mention SymPy, as well as presentations given about SymPy at conferences can be seen at SymPy Papers.
SymPy has a collection of official logos, which can be accessed here:
The license of all the logos is the same as SymPy: BSD. See the LICENSE file in the trunk for more information.
This is an (incomplete) list of projects that use SymPy. If you use SymPy in your project, please let us know on our mailinglist, so that we can add your project here as well.