Memory on the go

I bought some memory (512 MB DDR 333) for my home PC today, and - now thats the fun part - I managed to get that done between 2 consecutive underground trains (tube, metro, whatever you like to call them):

• Get out of the train
• out of the station
• across the road and into the shop
• ask for the memory, pay,
  
• get back to the station, see the train arriving (start to run),
  
• board the train and see the same persons that entered the platform when I left earlier
  

Train interval at that time was about 6 minutes.
Pretty cool, eh ?