Funny thing is, when recommending it to a friend, they mistakenly assumed from the title that it was a book of underhand tactics, which couldn't really be further from the truth. There's a lot to be said for being genuinely nice to others.
Then one day, you are desperate and you read it and wonder "my God why didn't I read this sooner!"
The interesting thing about the book is that it can be read in either light: as a Machiavellian guidebook, or as an earnest how-to about the principles of mutual friendship. Carnegie probably intended the book to be the latter, however, and that's the spirit in which I read it. It is very much worth reading. People can do what they will with the information in the book, but I hope they do good with it.
Most people I've told about this book have the same reaction, to the point where I suspect that Carnegie picked the title on purpose to get 'manipulators' to learn how to actually be good people.