After doing an initial search, I discovered that a lot of people speculate that Joseph and Imhotep are the same person. If you're curious, you can see two less-scholarly sites here and here. I was surprised to see that someone thinks that the stepped pyramid was actually created to store grain (for the biblical famine associated with Joseph). Seriously? I find that incredibly unlikely.
As I suspected, I couldn't find any reputable scholars discussing such a topic. It also seems unlikely that Imhotep and Joseph are the same person, since the Djoser pyramid predates Joseph's arrival into Egypt by about 1,000 years. (You can follow some of the theories regarding Joseph's historical timeline here).
I also learned a few new things about Imhotep during my research. He seemed like a very interesting and intelligent man. In addition to creating the stepped pyramid at Djoser (the shape of which is seen as the precursor to the sleek angles of the Pyramids at Giza), Imhotep was probably the architect for the step-pyramid complex Horus Sekhemkhet at Saqqara.1 By the Late Period (c. 750-332 BC, which is about two thousand years after Imhotep lived), the architect had achieved the status of a god. As a deified being, Imhotep was associated with medical learning and healing. There are many Late (and Greco-Roman) period statues of Imhotep seated and holding a papyrus scroll (you can see an example here).
If anyone can provide some solid, scholarly evidence to support a connection between the Joseph and Imhotep, I'd be interested in reading it. For now, though, I've decided that the apparent lack of connection is for the best. It's quite awkward to sing, "Go, go, go, Imhotep!" anyway.
1 , "Imhotep," in Grove Art Online. Oxford Art Online, http://www.oxfordartonline.com.erl.lib.byu.edu/subscriber/article/grove/art/T039994. Accessed 28 May 2010.
