Emulate a 7-segment display
C, 106

Size is 74 chars if allowed to rename program "W00WG5WW1GW66WG4WW2GW33WG"

main(int i,char**s){
    for(s[0]="W00WG5WW1GW66WG4WW2GW33WG";i=*s[0]++;putchar(s[1][i&amp;7]-49?i==71?10:32:42));
}


running:

./a.out 1101101
 ** 
   *
 ** 
*   
 ** 


notes:

'W' and 'G' (0x47 and 0x57) are chosen such that the value &amp; 7 = 7, i.e they safely index the null character that terminates the input string.