http://www.plastics.com
The best Plastic forums with the best plastic guru's under one roof + much more...
http://www.devicelink.com/
Probably the most useful and affective website for medical devices
http://www.polysort.com
More on the commercial side...not as good as Plasticsnet.com
http://www.neopharma.com
One of the best sites for B2B. Worth taking a look at
http://www.valueplastics.com
Very valuable information regarding male female connectors and drawings of technical components in pdf format
http://www.qosina.com
Largest collection (probably) of plastic components used in the medical devices