Another board game that I picked up during the US trip was Blokus. Like Qwirkle, the learning takes barely a minute. And the game can be played in 20-30 minutes with 2 or 4 players.
Games like these are fun time-fillers, and also make one think differently. They require much less thought that something like Settlers of Catan, which also I like a lot.
Somewhere, amidst all the distractions of TV, computers and mobile, we have lost the joy of playing board games. Games like Catan, Qwirkle, Ticket to Ride and Blokus bring that back.