Btw, I have already written something similar in perl.

I had to generate the sequence of (x,y) coordinates in spiral, something like this:

0,0
0,1
1,1
1,0
1,-1
0,-1
-1,-1
-1,0
-1,1
-1,2
0,2
1,2
2,2
2,1
2,0
2,-1
...
[download]

This was for an internet game. I wanted to discover the islands on a map with a ship in some order. This order is good becuse this way the ship travels only 1 units of distance in each step, so the discovery was fast, and I discovered the islands near my island first (as that's where the center of the spiral was).

Bots have since been banned in that game, so I have deleted the code. Sorry.