Those links are all to companies who have the puzzle sent in with the application, not given in the interview. Also, on that note, Joel Spolsky advises (http://www.joelonsoftware.com/articles/SortingResumes.html) that this will reduce the number of applicants you get, but not increase the quality. The reasoning is that, since great programmers will have options, including the problems will be equally likely to dissuade good candidates and bad candidates from applying and what you're left with will be desperate candidates that are willing to jump through any hoop. Perhaps just one take. Anybody that has used the with-application puzzles, how did they do for you?
As for in-interview questions, Joel also had some good advice (http://www.joelonsoftware.com/articles/GuerrillaInterviewing...), use two types of questions: (1) softballs, and (2) complex questions requiring a grasp of multiple layers of abstraction, like C pointers or recursion. With type 1, he recommends caring more about how quickly they do it than if they eventually get it right. For type 2, the goal is more to see how they think, and you're free to help them along with the trivia that is easy to forget but easy to find on Google in 15 seconds.
As for in-interview questions, Joel also had some good advice (http://www.joelonsoftware.com/articles/GuerrillaInterviewing...), use two types of questions: (1) softballs, and (2) complex questions requiring a grasp of multiple layers of abstraction, like C pointers or recursion. With type 1, he recommends caring more about how quickly they do it than if they eventually get it right. For type 2, the goal is more to see how they think, and you're free to help them along with the trivia that is easy to forget but easy to find on Google in 15 seconds.