I assume you're asking for a Windows solution, but I do have a solution if you have a spare box or old laptop sitting around, and can install some flavor of Linux on it (*cough* Debian *cough*). After setup, install a sync service like Dropbox or Copy, then install Motion.http://lavrsen.dk/foswiki/bin/view/Motion/WebHome
Welcome to the home of Motion, a software motion detector.
Motion is a program that monitors the video signal from cameras. It is able to detect if a significant part of the picture has changed; in other words, it can detect motion.
It's a command-line program, so it's very light on resources, the sensitivity, snapshot interval time, and snapshot folder location can all be set. So just configure it to dump snapshots in your Dropbox/Copy/SpiderOak folder, and voila'... remote monitoring.
For Windows, I know WebcamXP was one of the more popular webcam softwares around, and the free version has motion and audio detection.http://webcamxp.com/home.aspx
webcamXP Free and webcamXP Private now with Motion and Audio Detection. We have decided to extend the features of those 2 versions to allow everybody to put in place home security even with the free version. The only feature which remains specific to webcamXP / webcam 7 PRO is the continuous recording (DVR). A license for webcamXP Private allows supporting up to 4 cameras and removing or changing the webcamXP watermark displayed over the video streams and recordings.
Dunno other than that...