I'm trying to use 2 webcams for a computer vision application.  My
primary need is a reasonable frame rate on two of them at once.

I've tried two Logitech 4000 Pro's and the frame rate is terrible,
even at 320x240 -- under 10 fps.  It turns out these are USB 1.1
devices -- "The Logitech video cameras are compatible with the USB 2.0
specification, but not compliant. This means the Logitech camera will
function properly when plugged into a USB 2.0 port, but the webcam
feature will function with the USB 1.1 specifications."

I'm looking for an inexpensive (webcam price range) camera that I can
use at a higher speed for such an application.  Any suggestions?

Hi

How about the Creative, cheaper, decent reviews, 640x480 @ 30fps

http://www.amazon.com/gp/product/B00067KT94/ref=pd_bxgy_text_b/103-7939483-6809451?%5Fencoding=UTF8

http://reviews.cnet.com/Creative_WebCam_Live_Ultra/4864-6502_7-31297583.html?ctype=msgid&messageSiteID=7&messageID=1312534&cval=1312534&tag=uolst