I strongly recommend TWiT for any tech or gadget enthusiast. Also the techie blog lifehacker.com is great for newbies, especially anything written by Gina Trapani. Her articles pointed to a hefty fraction of the following insanely useful Firefox extensions.
Theme-wise, I like Arronax's GrApple Luscious for Firefox, because it looks pretty and conserves scarce toolbar real estate.
Last updated: 20090707