Trendnet
Trendnet TV-IP100 work ok. http://x.x.x.x/video.cgi
Trendnet TV-IP300 : Just remember to turn 1.0 in ZM_HTTP_VERSION in the Options > Network tab. In the x.x.x.x/cgi-bin/video.jpg gives 352 x 240 jpg.
Trendnet TV-IP400 / TV-IP400W: These are cheap but fun Pan Tilt Zoom IP cameras and are now also supported by ZoneMinder. For the PTZ driver and all installation/configuration instructions please visit: http://www.sfpeter.com/2007/08/14/controlling-the-trendnet-tv-ip400w-camera-with-zoneminder/
The above link is missing the "Move" tab when creating the control. You need to select "Can Move", "Can Move Diagonally" and "Can Move Relative". The driver does not appear to work on versions past 1.22.x - http://www.zoneminder.com/forums/viewtopic.php?p=39157&sid=684c4c7ff25a32a197fe586eed017274.