PL Club was really neat: Brian Aydemir talked about the recent ICFP '09 paper by Georg Neis, Derek Dreyer, and Andreas Rossberg, Non-Parametric Parametricity. Sitting down and talking through a lot of the definitions really helped my understanding of what Derek was talking to me about back during CADE in August. Paradoxically we hardly talked about the step-indexing bits, and yet I feel like my understanding of them has improved --- just by seeing that everything surrounding them isn't that scary after all.
There's still a bit about the discipline of names vs. variables that I think they are being fundamentally not-as-good-as-possible about though --- Benjamin suggested that it resembled the ubiquitous confusion in the π-calculus between channels names and channel-name-variables, and I couldn't agree more.
I tried the cheesesteak made by the little food truck across the street from Skirkanich with: onions, ketchup, hot sauce, and it was obscenely greasy and delicious. The hoagie rolls here they have are really good at getting deliciouser but not falling apart as the grease of the sandwich soaks into them.