Re: sewing in public -- I've found that people do stop and look more often when you're making a shirt. While everyone knows what hand sewing is like, most people have never imagined making shirts by hand, so it does draw some attention. The part that takes some ingenuity is how to arrange things so that people can tell it's a SHIRT from thirty feet away.
(That said, yes, it's much easier to draw attention when you are hand spinning.)
Chris, yes, arranging that shirt might be a bit of a problem... especially when you are in the very first stages of work and it's not really very shirty-looking. But since I have a number of different techniques to choose from, I usually take the easy way out and just demonstrate something that is inherently attention-grabbing.