Summary: The geko 201 is nifty. It's light, fits in a pocket, and it could save your life, I suppose. It doesn't have any maps on it, which is unfortunate, but that's part of what makes it inexpensive and portable.
Summary: I bought this unit due to its size. It is tiny and lightweight so I tend to carry it more often. It picks up a signal very fast and in conditions where others are still searching.... I can quickly pick up a signal in my basement! Very accurate as well.
Summary: This is a great GPS for Geocaching. The battery life is excellent, and since it uses regular batteries, it's easy to carry a spare set with you, so no worries about an internal battery going dead. This model is tough as nails, and still works despite my brutalizing it in the forests of Michigan.
Summary: My Geko 201 was subject to the so-called Y2K+10 bug. For any time period after January 5th, 2010 the GPS device incorrectly calculated the date. This resulted in an incorrect (dysfunctional) almanac which caused an excessive amount of time to be taken to acquire satellites.
Summary: As a skeptic about GPS, I bought the Geko only for marking maintenance needs on hiking trails. I found it was fun to play with, too. It is about the most reliable way to test the speed of my canoes, and navigating in featureless aquatic environments such as bays and estuaries is a cinch.