From a practical standpoint, an accuracy of a few hundred metres means that if you were travelling around the world, and just wanted to know which photos were taken in which city, it would be perfectly adequate, but if you want to know where in that city particular photo was taken it is going to be of limited help. The built-in card reader and compatibility with Picasa and Google Earth means that you can update your travel blog from an internet café in Kathmandu as easily as you can from home. For a device costing significantly less than a decent in-car navigation system this level of performance isn't too bad, but if you're looking for pin-point accuracy, for example for surveying or wildlife tracking then you will need to spend a lot more money.
More of a clever gadget than a serious navigational tool, the ATP Photofinder GPS Picture Tracker will be useful for world travellers and anyone into Geotagging, but its slightly hit-or-miss accuracy limits its use for anything more demanding. However it is well made, very easy to use, and the inclusion of a card reader and compatibility with widely-used free software makes it extremely convenient.