I have found a way to get the Image Capture application to update the interval at which the camera takes a picture.
I used Mozilla 1.4 to view the form. The realm name was my short username and the password was the password which I set in the Image Capture preferences. I set the "Shared Name" to be the same as the password I chose; this may not be relevant. With this method, I was able to get my Kodak DC4800 to take a picture every 45, 40 or 30 seconds. If I set it to take a picture more than 120 times per hour, it still "sticks" on a 30 second minimum interval -- perhaps this has to do with the type of camera, or the fact that I'm asking it to take 3M pixel photos.
Oddly, even though I have the Mozilla password manager checkbox set to remember the username and password for this realm, the browser asked for this info each time I wanted to change the interval. Perhaps there is a bug in the webserver portion of Image Capture in how it tells the browser what the relevant realm name is.
The *.js files in /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/ ImageCapture.framework/Versions/A/Image Capture Web Server.app/Contents/Resources make up the browser UI.
If anyone has already figured out what URL to get to grab the just-taken photo automagically, that'd be neat. It would take up hard drive space, but then the "Remote Monitor" portion need not be watched and the archived frames can be analyzed later for motion between frames for a useful security application.