I found one that is less obtrusive than some. It sounds more like a wind chime than a regular ring tone. Of course, any ring tone, however subtle, is going to get on your co-workers' nerves if you leave it on.
We're living in a world where technology is a huge part of our lives, but it can be a blessing and a curse. Some people think this technology can make us more productive. But it's not helping us with social skills. It's alienating us from other people.