I have taken glasses to both restaurants and to friends homes. I have asked the host of the party if they minded that I brought my own glasses, and no one really seems to care. They know I am a wine freak, and take the drinking of wine seriously, so they sort of expect the unexpected. As for reastaurants, I would be surprised it the wiater, wine guy, or host said anything to you for bringing your own stems. They may think you are a bit odd, but everyone seems to get over it after about 5-10 minutes. I just make an announcement, telling the hostess or host and the waiter that I have my own stemware and wine, and they say, "no problem, would you like me to open you wine now, or later." The first few times, I felt a little awkward, but now it's no big deal.