Because you can talk to your friends all day and night, even when you're sitting at the dinner table with your family, or in the shower...I suppose people find it cool, and easier. I personally find it a tad bit rude and anti-social and would much prefer talking over the phone. No offense, anybody, just my opinion.
well I'm probably considered old school, but I feel texting is a very impersonal way to communicate, especially with people you know well. It's a good form for getting quick and short messages to people when a call is more inconvenient or not appropriate. But it shouldn't replace or be used for long or intimate conversations. However, we live in a fast-paced, highly social technical world now, so its not a fad likely to die anytime soon!