How can I track the sales rank of an item on Amazon programatically?

I've seen several products that will track the sales rank of an item on Amazon. Does Amazon have any web-services published that I can use to get the sales rank of a particular item?

I've looked through the AWS and didn't see anything of that nature.

From stackoverflow DaveK

• You should be able to determine the Sales Rank by querying for the SalesRank response group when doing an ItemLookup with the Amazon Associates Web Service.

  Example query:

  http://ecs.amazonaws.com/onca/xml?
  Service=AWSECommerceService&
  AWSAccessKeyId=[AWS Access Key ID]&
  Operation=ItemLookup&
  ItemId=0976925524&
  ResponseGroup=SalesRank&
  Version=2008-08-19
  

  Response:

  <Item>
    <ASIN>0976925524</ASIN> 
    <SalesRank>68</SalesRank> 
  </Item>
  

  See the documentation here: http://docs.amazonwebservices.com/AWSECommerceService/2008-08-19/DG/index.html?RG_SalesRank.html

  DaveK : Thanks! Your solution worked perfectly. I signed up and got an AWS access key, switched out the ItemId and i'm in business.
  From Adam Hughes

• Amazon have changed their API so it now requires a signature: http://developer.amazonwebservices.com/connect/ann.jspa?annID=483 so the above example no longer works from August 2009 onwards.

  From ade