In recent years we have seen a proliferation of spin-offs from the standard pediatric texts, such as the venerable Nelson Textbook of Pediatrics1 and the even more venerable Holt/Macintosh/Rudolph Pediatrics.2 I am not aware of a spin-off as yet from Oski's Pediatrics,3 but it is only in its third edition. The pocket Nelson is one such product, as is the more comprehensive paperback version, the Nelson Essentials of Pediatrics,4 the fourth edition of which appeared in 2001. Residents and medical students with whom I consulted refer to various versions as "big" Nelson, "little" Nelson, and "baby" Nelson. In this era of Internet access to authoritative sites such as http://www.MDConsult.com and http://www.UpToDate.com, as well as availability of various textbooks online, it is altogether appropriate to consider the function and use of these products and the classic comprehensive textbooks. The preface of the Pocket Companion indicates that it is directed at medical students, residents, and "others in training" as a distillate of the standard Nelson textbook. It is intended to be readily carried in one's pocket, presumably in the standard white coat used by clinical clerks and at least some house officers. Accordingly, I made an informal survey at 2 institutions over a several-week period. Virtually all the house officers carried the ubiquitous Harriet Lane Handbook5; few would replace it for a pocket version of a full textbook, especially because they could readily access information online or already owned 1 of the standard comprehensive texts. Medical students preferred the softcover Essentials version of the Nelson, the Rudolph, or Current Pediatric Diagnosis & Treatment.6 These softcover textbooks provide a more complete yet briefer overview of a specific subject and are less expensive and more portable than the standard textbooks.