I have one of these and I like it a lot. It comes with some basic software to show you where you've been on a map as well as time-based graphs of your pace and heart rate. You can also export the data to a few websites (MotionBased, etc) that will pair your data with better maps and external data like weather etc. If you like to run/bike/walk and like data, this is a nice gadget. I paid about $300 for mine two years ago.
However, this is the older model. It has been replaced by the 305, which is smaller and has better sat reception - but costs about $100 more. My oly complaint is that I do sometimes have to wait up to 10 mins to get a signal lock but I've just worked that in to my stretching time before a run. For ~$150, this is a nice deal.