hi KPR. i don't think SEs like any URL that involves some sort of redirection, including the one i suggested. but they still do index the pages and assign PR weights--just not to final page they end up on (in this case, say, innocuous.php could get a PR value of 2 because of all the content on
http://some/url/with/an/affiliate/id/, but that URL itself would not get any PR weighting due to innocuous.php). well, that's my understanding of it, though i'm no SEO authority. either way, when dealing with affiliate id hiding, SEO concerns are usually not high on the priority list for the affiliate.
Stephen, if you try out Red Queen, don't hesitate to query me about the program. i used to spend my time solely coding for that application. then one day i decided i needed a decent demonstration of the thing in action and started looking around for a way to use it. it didn't take long for me to realize that it had a place in affiliate marketing, so that's the road i'm heading down now. early days for me in that area, though. but it looks promising.