This is a list of sites with some relation to paleoanthropology. Many sell casts of hominid specimens, models of hominid specimens, real bone material, professionally made slides, or anything else that I think might interest anyone who comes to this site. If you have any suggestions, please let me know.

Bone Clones - High quality casts and reconstructions, though a bit more expensive. Definitely worth it in my opinion.
Hamman-Todd Casting Program - A professional cast producer with a wide variety of specimens available.
Online Dissertation Services - A source for relatively inexpensive doctorial theses.
Pictures of Record, Inc - A good place to buy premade slide series on archaeological subjects. Includes a couple of paleoanthropology slide series.
Skullduggery - A company that provides casts of some fossil hominids. The prices seem less expensive here ($110-$140), but I am unsure of quality.
Skulls Unlimited International, Inc. - A very good company that provides teaching quality casts of some fossil hominids for reasonable prices ($50-$190). Has a wide selection of other fossil replicas as well as real osteological material.
The Bone Room - Another company that sells casts of some hominid specimens. Prices are mid-range ($100-$150), but I am unsure of the quality of the casts.
University of Pennsylvania Casting Program - This is a professional cast producer, with higher quality and higher costs, and much greater variety of specimens available. There are casts available in three different materials (hence, three different prices) per specimen.