PLC related websites

Control Engineering
http://www.controleng.com/

Automation World
http://www.automationworld.com/

Industrial Design Line
http://www.industrialcontroldesignline.com/

Control.com Forum
http://www.control.com/

plcs.net
http://www.plcs.net/

MrPLC.com
http://www.mrplc.com/

IEC 61499 related information
http://www.holobloc.com/

More links to follow.

Nice Industrial Ethernet Blog from Lynn Linse

I just came across this very nice website of Lynn Linse who is an expert in Industrail Automation Protocols.

Main site: http://iatips.com/
Blog: http://iatips.com/blog/index.html
Wiki: http://iatips.wikispaces.com/