Purchase nitrogen gas. Breathe that in instead of Oxygen. It looks like a peaceful way to go. http://lostallhope.com/suicide-methods/plastic-bag-gas

That said, life has a lot going for it. There are always cool things to do, people to meet, laughs to be had, love to be given etc... Failing that, go browse lolcats for a while.

Also, this may help: http://www.youtube.com/watch?v=0zBoD_ojxFA, or possibly this: http://www.youtube.com/watch?v=XlgQxK-HBGk both of which help perk me up.

Also, consider doing something a little crazy. I'm sure your bucket list isn't blank. Pick something outrageous and do it. Then repeat. Death comes soon enough.