I read Lifehacker: 88 Tech Tricks to Turbocharge Your Day which was surprisingly available in the NLB. A lot of it is already covered in The Best of Lifehacker in Upgrade Your Life [1] (the set of sources for the second edition of the book). Here are a few things that were new and interesting:

1. Using Flickr to capture Business Card Details. Also tag them so that they are easy to search and make sure you keep them private.
2. Store fitted bedsheets inside pillowcases. A great idea to save space while packing for moving (which I am doing currently!)
3. Mirror entire websites using wget. The command is wget -m http://<website-address>
4. Using Google to look up synonyms.Use "~" next to the keyword you want to look up
5. Useful Bookmarklets are listed on Lifehacker [2]

I would definitely prefer a PDF edition as the book is worth keeping as a reference. But the Lifehacker post - The Best of Lifehacker (linked above) - already covers most of the book.