Cache Register is a compact utility program, designed for the DeLorme PN Series GPS receivers. It works directly with Geocaching.com to facilitate truly paperless geocaching. It comes in the form of a widget, which is a very compact program that uses very little in the way of memory or screen space. The widget is downloaded from DeLorme's website, and is easily installed on any PC or Macintosh. The cost for downloading is exactly zero dollars. It logs directly into Geocaching.com, and reads, downloads and manages geocaches, and can upload logs and field notes to Geocaching.com for geocaches that you have found. The only drawback is that it requires a Geocaching.com Premium Membership, which costs about thirty dollars a year.

A pocket query is a list of geocaches and the associated data, selected from Geocaching.com's enormous database of geocaches hidden all over the world. By applying a large number of available criteria, you get to specify what kinds of caches to find. Among the parameters are the geographical area or location, the size of the cache, how old the cache is, whether it has been found before, who placed it and when, how difficult it is to reach, and much more. The results of a Pocket Query can vary greatly depending on what the user specifies as criteria. For example, a user can request all caches within 10 miles of a given location, that he has not yet found, that have been placed in the last 2 years, that are on easy terrain. Such a query could easily return thousands of results.

If the query finds over 500 caches, it will stop. That is a built-in limitation of geocaching.com. The user can refine the query to ask for a smaller area, specify a shorter date range, or other criteria, to reduce the number of results. Once the user is satisfied with the results, the query is available for preview and also emailed to the user. It can be downloaded as an e-mail attachment and be used with other supported GPS devices. Cache Register retrieves the query results directly from Geocaching.com, and handles downloading it to the device. This makes Cache Register a very convenient method of managing caches.

Cache Register then allows the user to transfer all of the queried geocaches to the PN-30, PN-40 or PN-60, up to a maximum supported number of caches, depending on the model. For the PN-30 and PN-40, the limit is 1000 geocaches and waypoints stored in the unit. If there are waypoints stored on the machine, the number of geocaches is reduced. Conversely, if the machine is full of geocaches, the user might not be able to create waypoints.

Cache Register will also manage the results of Pocket Queries independently of each other. It will allow the user to delete or load any or all of the caches of any query at one time. If the user had multiple queries they could select any query and have all of its results unloaded at once. This is a very handy feature for someone geocaching at multiple locations. They could unload all the caches near one location with one click, then load all the caches from a new location, and do the reverse upon returning.

In order to use Cache Register, an update to the PN-series device firmware may be needed. The added functionality of the firmware update allows the field notes to be added to the geocache record, so that Cache Register can update the field notes on Geocaching.com. And using it is beyond easy. It logs into Geocaching.com automatically, and lists all of your available pocket queries. At the same time, it uploads any pending field notes. You can select the queries you want to work with, and Cache Register loads or unloads them. At the same time, any pending field notes are added to the caches that you have already logged. That's it.

Nerds in the Wood recommends that anyone who does geocaching with a DeLorme PN-40 or PN-60 obtain this widget. This is an indispensible utility, and it is free for DeLorme owners. It is every bit as good as any geocaching utility program and will make owners of other GPS brands envious.