Obtaining Benzene from toluene
There is also a disproportionation reaction that converts toluene to a mixture of benzene and xylene (Bawa et al), also, see wikipedia.  It has commercial applications (because the benzene/xylene mixture can often be sold for more than toluene) and can be licensed.  However, it is more of an industrial process than one you would use in the lab, as it is really driven by an exothermic dealkylation in vapor phase over zeolite catalyst.

Interestingly, as zeolites act as a Lewis acid, this is strangely similar to Friedel-Crafts alkylation, which uses Lewis acid catalysis in liquid phase.  The paper by Bawa et al discusses experiments in which the trans alkylation was done with Frieden-Crafts catalysts in liquid phase.