I guess I'm more in Phoenix's camp here, having heard that line more times than I can count. I would agree that if you perceive a serious suicidalness (along the lines of that link), absolutely call 911.
I have called 911 once. But mostly, I've used Lexi's "You're right. If easy is what you're after, it's easier to be dead. Life is complicated. For everyone." And then moved on with whatever I was doing.