I was reading Lacey Sugarman's article on subway knitting in the new Knitty, and was struck by this:
Although knitting needles occasionally constitute weapons in airports, on the train, they disarm. They instantly made me more approachable and other passengers less creepy for approaching me. It turned out that knitting did, indeed, reduce stress.
I have talked with many about how knitting soothes the multitasker in me, allowing me to find joy in conference calls, bus waits, commutes (where I am not driving) and slow movies.
But this is a fascinating point, knitting, rather than isolating you from the group as some other solitary pursuits can, creates a conversation point. People can ask what you are doing, talk to you about crafty things, or just watch.
One Knit in Public Day I sat in Starbucks and knit and had lovely conversations with two women - both started with them asking about knitting and then moved on to subjects like dating and movies. But knitting was the thing that made it not weird to start talking to a stranger.