fading a light

Can someone please tell me what IC to use to fade this: http://cgi.ebay.com/ebaymotors/LED-STRIP-30CM-BRIGHT-EFFICIENCY-REPTILE-LIGHT-12V-RED-/140399018407?pt=Motors_Car_Truck_Parts_Accessories&hash=item20b06f01a7#ht_5317wt_939

...I've tried using the mosfet: http://www.sparkfun.com/products/10213 ...but it doesn't fade, it just is either ON or OFF

I've searched for fading, but find thousands of topics. If someone could just tell me what chip I need, I can search it out. thanks,

The MOSFET should work. Make sure the pin you connect it to is one of the PWM pins, otherwise analogWrite() will turn the pin LOW for values below 128 and HIGH for values above 127. The PWM pins on the Arduino are D3, D5 D6, D9, D10, and D11.

THANKS! I was on pin 12 Too bad all problems aren't that simple!