If you are just interested in marking waypoints and want a cheap option, look on ebay for the eXplorist 100 or 200 by delorme. I recently picked one up for $35 and it works great. The manual was downloaded free from the delorme site. The 100 has no maps and can't be hooked to a computer, but the 200 can and there isn't much difference in price. These are very basic units, but if you are just looking to mark waypoints, they pick up satellites very well and are WAAS enabled which improves the accuracy considerably.