One site that I read faily regularly is called 43 Folders. It's a collection of useful stuff, mostly highlighting programs for the Mac and productivity tips. He's pretty taken with GTD and if you don't know what that stands for, go here.
This past week (the first of the month, actually), it had a helpful list of "hacks" that you could follow to improve your productivity. For example:
1 -- Pencils are a great way to write things down.
2 -- Sharpen new pencils soon after you’ve bought them, so you can use them to write things down more easily.
3 -- Make sure you put gas in your car, or it won’t run very far after you’ve bought it, and then you’ll have trouble getting to work.
There's a lot more on the list. See for yourself.