Here are some web site links that can give you some ideas for using the GP2D02IR distance sensor.

http://www.mcselec.com/an16.htm

http://www.acroname.com/robotics/info/examples/GP2D02-4/GP2D02-4.html

http://www.6502.org/mini-projects/gp2d02/gp2d02.htm

http://www.wirz.com/info/gp2d02/

http://home.twmi.rr.com/brouillette/gp2d02/GP2D02_2.html

http://www.imu.hjem.wanadoo.dk

It is amazing what one can find on just the first couple of results pages using the gp2d02 sharp search key at www.google.com.

Hope this helps.
Michael Karas