I thik those aplasticy ones Julia stated...
CircuitCity has them for $169
http://www.circuitcity.com/ssm/West...sem/rpsm/oid/184239/rpem/ccd/productDetail.do
Now yoiu can gets the 250 IDE drives indepelently. http://www.newegg.com/Product/Product.aspx?Item=N82E16822136159