Awesome! It's everything you ever learned in school but forgot and suddenly needed to know.
I saw Pocket Reference on Mythbusters and asked for it for a present. Well, the gift giver couldn't find the pocket version, so I received teh Desk version instead!
The book is full of practical information for doing things and building things. It's also handy as a reference for writers.
Especially helpful? The conversion tables. Especially geekily fun to know? The "10 codes"--such as the actual meaning of 10-4, good buddy.
Why did I give it only 4 stars when I think it's so awesome? Because there are ERRORS (the horror!). Simple misspellings abound. The "insert apostrophe" proofreader's mark is incorrect: they just took "insert comma" and turned that symbol upside down, showing you insert a "6" open single quote instead of a "9" apostrophe. To not proofread your proofreader's marks? Bad form.
It's all those little mistakes that could have been solved with a little bit of proofreading that lost a star for me.