Heh, most people I know who make pipe bombs are working on getting themselves killed.
However, homemade bombs is a subject that interests me a great deal. Fun on halloween.
I have only made a few pipe-bombs, and only ever dropped them down storm drains for fear of shrapnel, but what I did was pretty simple; make sure the caps are welded on tight and insert the powder through the side.
One thing that has always struck me about idiot anarchists is how dangerously they make pipe bombs. I always made sure that I put a paper bag between the metal and the black powder.
I have to admit, I found pipe bombs kinda boring. They were just loud, and that was it. We couldnt just throw them around for fear of shrapnel, and we had to put them down storm drains, so we never saw any actual explosion, just a jet of water.
Filling those little orange kinder surprise things with black powder and the stars from a dissected roman candle is way more fun. It looks like a multicoloured phos grenade.
As for incendiaries, they're fun, depending on what it is. Thermite is fun, you can seriously do in someones car with that stuff (I never did it). Napalm is entertaining the first time, but gets boring fast.
One thing that I have only done once and would like to try again is a pipe bomb made with vinegar and baking soda, its quite fun.