Ooh! I know the answer to this one.
"By staring at passers by with my decapitated head held in my hands."

I came across this idea a while ago, and if I ever get to the stage of committing suicide, this is how I shall do it:

Go up on a roof, armed with glue, poles and a rope the height of the building less a few feet.
Tie the rope to something sturdy, and also to your feet.
Arrange a chainsaw or something, I don't know (the original poster had wire but you'd have to try really hard to get that to work) at the edge of the roof at neck height.
Glue your palms, then reach under the sharp thing and hold the sides of your face.

And finally, hurl yourself through your head-remover and off the edge, ending up dangled at head height with your severed noggin clasped in your hands and staring at passers by. Paint your face for bonus points.

Alt Q: I doubt I could hurl myself off the top of a tent to the same effect, so pub crawl I guess.
(Falstaff's Spiritual Successor, Fri 27 Aug 2010, 14:23, Reply)