OK, so I greased up the wiper mechanism and now it moves smoothly! Thanks everyone!!! It's at least fixed for the moment.

Now for the bad news...I somehow broke my combo switch (the part that turns the wipers on) so that I only have interval and off position. I live in Seattle and it's now winter...so I definitely need 2nd and 3rd speed. Anyone know how to take the combo switch apart so I can see what's going on in there?