This is my new running gadget. I have been somewhat reluctant for a long time to buy a GPS and/or heart rate device, because I kinda feared that it would interfere with the main purpose: running. I feared becoming a slave of all those technical devices and lose some of the freedom involved with running. The best thing about running is that you basically just need to put on your running shoes and walk out the door and that's it. Well, I decided to bury my fears and give it a try. I also decided to do it properly, so I bought a high quality device with both GPS and heart rate monitor built-in. It's been a pleasant journey so far. I decided to buy the rather big (some would even say clumsy) 310XT model, because it can display (up to) 4 different values at a time and in a readable size, it has an outstanding battery time of some 20 hours effective use after being charged, it is water/swimming proof which is good when riding my MTB in a rainstorm (something that has happened several times in the past) and last but not least it has a vibrator which is very nice to attract attention towards lap messages etc.I love the automatic meassurement of distance and especially the auto-lap feature that gives you an average pace every 1km. Also the ghost-runner mode where you run against a given pace is excellent and extremely motivating to squeeze out that last bit of determintation to beat your current track record.I also like the Garmin Connect web application. It could be better of course, but it's good enough for me and it's great to sit and read all the data and see the route map, when back home again (the data are transferred wirelessly via a USB device that connects with the 310XT.) I hope Garmin also releases their promised web service sometime soon, since I would like to use it to build features on my own website. But so far they have been very quiet on this.The not so good bits are that it often takes several minutes to get a GPS lock, especially in cloudy weather (maybe they should team up with a phone company and build in some assisted GPS to speed it up in future models?) When the lock is achieved it is however very accurate for the entire run. Also it seems to be very unreliable to auto-start when entering a known route. So far it has failed both times I've given it a try, so I've defaulted to a manual start even on a known route. I think it is a bit disappointing that this feature doesn't work better.All in all I'm glad I've entered the GPS running device age and I'm sure I'll have a lot of fun with the 310XT on my future runs and also when analyzing the data afterwards. There's a lot of room for improvements, but I'm sure we will see more and more advanced devices of this type in the future.