CafePress just announced black t-shirts are available for its' members to use. Hot diggity damn. I was planning on switching from CafePress for this very reason, although that might still happen; the alternative site I found has a lot more variety in the products (a lot more colors than five), without some of the sillier stuff that CafePress has (not a bad thing, though).
Of course, "soon" is a relative phrase; I still don't have internet at home, and won't until I'm not spending $940 a month in collective rent (I'm not kidding; that's how much I'm spending right now). However, as soon as I'm online, I'll be working on the new files.