Thank you for this link as well. It is an important subject and one that I am well familiar with. I have struggled with suicidal tendencies for a long time and was hospitalized at one time. I would add a couple of things to the good suggestions already listed here. Yes, it is important to remember that tomorrow is another day when circumstances or emotions may change. And yes, suicide is not a way to get back at someone who hurt you. No one else should have that much influence or control over your life.
Having been through this, I would also like to add this:
*If someone speaks of suicide or says things like "I wish I wasn't here...It would be better if I could just die..I wish it were just over," do not take it lightly. Do not dismiss it with comments like, "Oh, stop it. Come on, don't be melodramatic. Your life isn't that bad...etc, etc." I could go on and on. The person who feels suicidal has lost all HOPE. Telling them they shouldn't be feeling what they are definitely feeling does not help them. It only makes them want to shut down, to not communicate the feelings. Personally, I think the best thing is to listen, to express concern for them, to ask them to not take any immediate action and to promise to call someone if they feel they are getting too overwhelmed. Obviously, it's also good to try and get them to speak with a professional.
But those who are feeling this way are in very serious pain. I'd also like to add this thought. The pain doesn't go away, even when it may appear they are no longer talking about suicide. For others surrounding the suicidal person, they believe as long as the person doesn't make an attempt, all is fine. But for the person feeling this way, they are still in the pain. They may not make any attempt for a number of reasons...fatigue, their concern for children, spouses, famly or others in their lives, their faith, or a lack of opportunity to carry it out. BUT, it does not mean they will not at some point make an attempt and it does not mean the pain has gone away.
I think most people really underestimate the depth of pain that has prompted a person to feel suicidal. They need to hear someone wants to really listen to them, to care about them, to understand their pain. The best thing you can do is spend time with them, even if that means just sitting with them.
From personal experience, I can tell you that it is often a lifelong struggle against giving into the temptation. Logic and common sense don't play into it because the pain can be so great...pain and total and complete hopelessness. If you can offer these people a smidgeon of hope about anything in their life, it can help.
Just my two cents.