I think mmarsh may be confusing himself with the F-22 and F-35 aircraft, both which can mount external weapons on removable pylons at the cost of greater radar visibility.
I call myself a military aviation nut, but never before have I seen any sources which say the F-117 can carry Sidewinders. This may just be because most of the books I read are pretty old so the information might not have been released at the time of publication.
Also, I don't think it makes any sense to carry Sidewinders. The F-117's bomb bay is very small, and its primary mission is as a bomber, so it doesn't make sense to waste space with air to air missiles. The entire point of the plane is to stay hidden, so it won't go out of its way to hunt other planes like that. And since it is quite sluggish and unmaneuverable, the best course of action if caught would be to try and hide again, not to fight back.
Are there any flyboys in here who can confirm this out of personal knowledge/experience?