While I would never think of lugging my own linens to a restaurant or supplying my own stemware, I have been known to bring along a bottle of my own wine. In fact, I'll go out of my way to patronize a place with a friendly corkage policy. (Corkage is what restaurateurs call what they charge to open and serve your wine.)
It's not that I'm cheap (although I'll admit I take a 400 percent markup on Pinot Grigio more personally than most) or that I don't respect the hard work (and money) that goes into making a great wine list. It's just that sometimes I want to drink one of the hundreds of wines gathering dust in my basement with a meal that isn't homemade... no offense to my husband, the family chef. Add special occasions like birthdays and dinners with our friend The Collector (a lawyer who pulls bottles of La Mouline from his pockets the way others do mints) and I'd guess I bring wine to restaurants about three times a month.
I know that BYOB isn't something most restaurants are fond of, and I'm sure it's something their accountants don't approve of... after all, food can be marked up 40 percent on average, while wines can be marked up 10 times that. No doubt that's why so many New York restaurateurs tell customers it's "illegal" to bring their own wine. (It's not, though it is in some other states.) Some may charge a high fee (in part to discourage the practice), some just a little (enough to cover the dishwasher's time), but in either case, corkage is generally meant as a courtesy for customers looking to savor a special bottle.