Yeah, i think suicide is definetely justifed in some cases. People who are in great physical, permanent pain should not be forced to endure it if they truly desire not to. Its not like they have much to look forward to except dying a slow miserable death.
Now, people in great mental pain is a lot more blurry. I think it is justified in SOME cases. Like my situation, for example, would be justified (at least, in my opinion). Because, a lot of my mental problems are pretty much permanent. But, the people that kill themselves just because someone broke up with them (or something else along those lines); well, that seems kind of pointless. That kind of pain will eventually pass.
anyway, thats my two cents.