Code:

---

int rand7()
{
  int answer = 8;
  while(answer>7)
    answer = rand5()+rand5()-1; // number between 1 and 9
  return answer;
}

---

best i could do in a minute. sort of elegant, but could potentially be an infinite loop (theoretically, but i think a computer's "random" table would cause a number 7 or lower to pop up fairly quickly).

julz

EDIT: oooh sorry! just realised while eating that each number does not have equal probability of turning up -- it's similar to the probability of '7' turning up when throwing two dice being higher than any other number.