For tracking the IP of someone connected to yahoo messenger , u have to make a direct connection as everybody has told. But for making the direct commection send him a file by picking up a file in options of yahoo messenger. Then while file is transferred it will set up a direct connection with that person . Then do "netstat -n" on the DOS prompt. U will get the IP address of the person .....

TRY THIS U WILL DEFINITELY SUCCEED

GOOD LUCK