I have to say, thanks for asking this! I've always wondered, too, how folks carried their own dressing (I live an hour from town, so my dressing would be sitting in my purse for minimum an hour and a half before I used it--sometimes 8 hours!).
What I do, at restaurants, is ask for their balsamic vinegar cruet, or wedges of lemon, or a bowl of salsa (whatever seems most likely for them to have) to top my salad.
[Off topic, but while I'm at it] Of course, my main objection to eating salad at a restaurant is that it's COLD! Brrr! At my favorite restaurants/bars, they bring me a glass of hot water as soon as I get there, and they keep it comin'! I tip big for my glasses of hot water, too! I really wish that there were some soup or something (most places here look at me crazy when I ask for a plain baked potato--they don't HAVE pain potatoes, they all come in already cut and oiled for prep) that I could get the minute I walk in the door...
5'3" tall, 63 YO. Started Jan. 11, 2010.
Thank you, Dr. McD!
Maintenance and Vigilance - Norm