Originally Posted by Seattle Forrest

A few things:

(1) I use that feature on a regular basis, literally every time I ride with cell reception.

(2) What you're talking about is actually the reason companies make more than one product. For example you can buy a 510 that does Live Tracking, or for $100 less you can buy a 500 that doesn't. If you don't care about or understand a feature, you shouldn't pay for it. That doesn't mean other people also find something unimportant.

My girlfriend wants to know when I'm coming home, if I don't use Live Tracking she'll text or call me during my ride to ask. If I do use it, she has a cold glass of iced tea waiting for me when I get home.

It doesn't actually tweet your position on a regular basis. The watch or computer sends your position to the phone which relays the data to a server. When you invite people, they're given a link which pulls your data down from the server. Twitter is one way you can send the link out; I don't have a twitter or facebook account so I just use email.

It's a neat system in that it combines the strong points of the phone with those of the watch. You could do the same with just a phone and a third-party app, but GPS is hard on phone batteries and you would get much less time out of it.