Electronics and Technology

http://www.electronicsweekly.com/Home/Default.aspx : Electronics Weekly, for the latest Electronics News.

http://www.engadget.com/ : endgadget, for the latest gadgets and technology.

Physics

http://physicsworld.com/cws/home : IOP Physics World, for the latest Physics News.

http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html : HyperPhysics, Georgia State University :"an exploration environment for concepts in physics"

http://www.sosmath.com/ : S.O.S Mathematics, useful for all : "your free resource for math review material from Algebra to Differential Equations!"

Renewable Energy

http://www.renewableenergyaccess.com/rea/home : Renewable Energy Access, for the latest Renewable Energy news and info.

More to follow...