Wine Etiquette
Typically, when you're out with friends they want to talk to you, not watch you stare trancelike into a wine list. So rather than hogging the wine list for yourself, ask for lists all around. If the list is some big, leather-bound novel, the restaurant probably won't have enough for more than one per table, but small, cheaper-to-produce lists are often in good supply.
If joint custody of the wine list doesn't spark debates about what to drink, you'll have to work a little harder to involve the table. Ask people what they like and dislike. Throw some suggestions out there. Whatever you do, don't be a rude wine geek and lose yourself in the list.
Business Dinner Etiquette
Business dinners are a little trickier, as there isn't the level of familiarity and casual social air of dinner with friends. Still, it's important not to disappear into the wine list and leave your business companions outside.
If you're the host, you have control of the list, but show your guests some respect and take interest in their likes, dislikes, and interests. If someone else at the table is very into wine, you might even want to hand the list over.
If you're the guest at a business dinner, and some twist of fate lands the list in your hands, be careful not to abuse that honor. Show your hosts the same qualities they'd want to see in you as a business partner: social grace, financial responsibility, and thoughtfulness. That can be a tall order in the already charged setting of a business dinner, where you've undoubtedly got bigger things to worry about, but here are a few tips that will make it easy:
Follow those tips and you're likely to come across as impressively confident, smooth, and thoughtful. You've got a jump start on sealing the deal whether they like the wine or not, but it's always better, for business and pleasure, when the wine impresses everyone as much in taste as in idea. How can you figure out which bottle will satisfy everyone? You can never know for sure, but you can make some pretty good guesses, especially if you start with the sommelier.