Hi guys,
thanks for the responses.

In the interest of ruling out the sway bar, I put pictures of its connections up at http://cs.uchicago.edu/~wes/van.html  (first is left side, then right).  Everything looks a little worn, but then again, both sides seem pretty much the same....  (It's the right side that's acting up.)  Thanks for taking a look.

-Wes