Instead, if you DO want to buy them a book, I recommend Tim Ferris - The Four Hour Work Week or Getting Things Done by David Allen.
Both those books are enjoyable for their content and suggestions, and also for a relatively scientific approach to showing why their methodologies work - which I think is why they both resonated so much with me.
I agree with the wishlist comment as well. For me personally, I have told my friends to stop giving me gifts and do likewise. I imagine I am losing some manner of social lubrication due to this decision, and compensate by sending personal emails and spending more time keeping in touch via facebook etc.
I also like to send postcards when I travel, for similar purposes.
I'm not saying that gift giving is selfish - but I am saying if you opt NOT to give gifts, as I do, then you need to be aware of the social ramifications and adjust accordingly. I do not have a perfect solution to this problem yet however.
one of his article is in the ycombinator library (good sign as hacker types like this book)
http://ycombinator.com/lib.html -> If You Want to be Rich, First Stop Being So Frightened. Fear of failing in the eyes of the world is the single biggest impediment.
http://www.timesonline.co.uk/article/0,,2092-2291061,00.html
http://www.amazon.com/How-Get-Rich-Greatest-Entrepreneurs/dp...
Though not necessarily targeted at the HN crowd, http://www.uncrate.com has some neat stuff.
http://www.amazon.com/gp/registry/1AC761X0H14R9?tag=foohack-...
:)