Living without your MacBook Pro
Fortunately, my department has several labs with iMacs as well as another MacBook Pro being used for research purposes, so I very quickly had two back-up computers to use, albeit without my own data.
And two days later, I had my own MacBook Pro back, with a new NVIDIA chip, new logic board, and a new 160 GB hard drive with all my data copied onto it (side note: how did I accumulate 95 GB of data -- time to do some spring cleaning on the ol' hard drive).
Phew -- life returns to normal. I was worried there for a few days...