I've had a lot of people reach the site from google looking for information about using their canon A70 (or similar models) as a webcam. Having got the Cam4You utility to work I thought I'd give a quick run through of the how of getting it to work.
Step 1: Install Application and turn camera on
Sensible really, but install the cam4you utility and when thats done turn your camera on in the "preview" mode, while connected to your computer. You should then, when running the application see the following image:
Choose "Pictures->Take picture remote" from the menu and continue.
Step 2: Configure Directories and Start Remote Connection
Next, choose the download directory, and any settings you want and then click the "Start Remote Process" button.
Step 3: Setup webcam settings
Next, go to the webcam tab and enter the filename you want the webcam file to have. This can then be uploaded on a regular basis using whatever program you want to your web-site.
Step 4: Configure Timings
Finally, set the timings. You can set a start-time, which must be in the future else the application will not work (if you want it to start straight away then untick the "Use Start" checkbox.
Set the interval - every 10 minutes, or whatever you decide (every hour even).
Then set the end criteria, if any, either stop time, maximum number of pictures, both, or neither. If the stop time is in the past it will never stop :D
Then click the "Start taking pictures remote" button. If this button is grayed out then go back to the first tab ("Remote") and click the "Start Remote Process" button again. If the camera fails to take any pictures (or the Time left to next shot counts UP) then check the start time is in the future, not in the past!
Again, you will probably need both a tripod of some description and a power supply, so be warned. Finally, there are lots of settings you can fiddle with, compression quality, size of image, zoom, exposure etc but I shall let you play with them. Enjoy.