I had quite some fun playing around with it to obfuscate code. I did find that jumping to a different position in the same expression broke on a lot of compilers as soon as optimization was turned on.

Here's a simple program to output a string with the characters in an unusual order.

    #include <stdio.h>
    #include <setjmp.h>

    #define J(x,y) (longjmp(x,y),0)

    int main(int argc, char **argv)
    {
        jmp_buf j[011];
        int x,X=0;
        signed char* i = " eehcef lo u ef'oYurls " +021;

        (x=setjmp(j[X++]))?J(j[x],*++i):((x=setjmp(j[X++]))?J(x[j],*--i):((x=
        setjmp(j[X++]))?J(x[j],(putchar(*i),*i+=128)):(x=setjmp(j[++X]))?((x<
        0)?J(1[j],5):J(2[j],3)):(x=setjmp(j[++X]))?((x>>X)?J(1[j],6):J(1[j],3
        )):(x=setjmp(j[++X]))?((x&0x80)?J(1[j],7):J(1[j],5)):(x=setjmp(j[++X]
        ))?(((X<<5)&x)?J(1[j],4):J(2[j],X)):(x=setjmp(j[++X]))?((x&128)?J(0[j
        ],X):J(2[j],4)):(setjmp(j[3])>=0)?J(j[2],6):0));

        return 0;
    }