Seems like a good time to revive this old thread.
I've done this myself, but only with the end, not the whole cigar. I like to blow out through a cigar toward the end, let it go out, put it in a pipe with a conical bowl so it fits in snug when I press it in, cut the extra off with a razor, especially everything that's partially burned already, and light 'er up. Good to use a not-so-fancy pipe in case you scratch the rim, and it may take some poking with the tool to open up the tobacco a bit, and it may need to dry out by resting for a day or so, but it's an extra bowl that I wouldn't otherwise have had. One warning: Way more nicotine that any pipe tobacco I've ever had, and more than the original cigar too, because it's had all that time to build up in the end.