Right now you can get the Machinery’s Handbook 28th Edition on CD ROM for $67.89 at Barnes & Noble.
I was skeptical about the utility of the Machinery’s Handbook CD when I first heard about it but I’ve been using mine (27th edition) for several years now and find it incredibly handy! The CD ROM has all of the text from the print edition, plus chapters from older versions of the Handbook that were cut over time. The ability to search the handbook is profoundly useful as it cuts down on the time spent leafing through the index. What I like best about it is the ability to print various charts and tables from the book for use in the shop. It’s cut down on the greasy smudges left on my print edition when cutting threads… as well as the irritation trying flip between several pages when doing calculations. It’s also a handy adjunct when doing CAD drafting; I can look up dimensions and insert into the CAD drawing easily. The only feature I don’t use are the online calculators — anyone use those?
Machinery’s Handbook 28th Edition CD ROM [barnesandnoble.com]