In honor of the holiday
Although I had previously been to this site, it was only upon revisiting it in honor of the fourth of July that I realized it had been put together by Dan of Dan's Data fame. I'm speaking, of course, of the page on how to make a sparkler bomb. It's quite entertaining reading, and this related link has some fantastic pictures.
Unfortunately I was unable to construct a sparkler bomb this year, as I didn't really have a nice, out-of-the-way place to set off such a device. I'm keeping my fingers crossed that next Fourth of July will be spent in BFE; these things just look too fun to pass up.