Texting Etiquette

One of the main things keeping me from being a full fledged Generation Y is texting. It's costs too much and honestly I just don't have enough friends. So I've often assumed my frustration with texting in public was because I don't fully understand it. What should and should not be socially acceptable? Here's a good rule of thumb:

If you're in a situation where you'd excuse yourself to go to the bathroom, you should also excuse yourself before reaching for your phone. Otherwise, go ahead without asking. Either way, don't play with your phone longer than you'd stay in the bathroom.