With Tolya (Anatoly) Vershik, Saint Petersburg, 2003
Peter Frankl and Voita (Vojtěch) Rödl, NYC, summer 1986 (or 1987). This post mentions the Frankl-Rödl theorem.
Jeroen Zuiddam at IAS, a few days ago. (See this post)
We just moved to a new apartment, and I discovered in the process a few old pictures. Here are two pictures from the late 80s and the early 2000s (I may add a few more later) and a fresh new one from a recent short US visit.