So I recently installed Latitude on my computer (my Blackberry doesn't actually have a data connection, and they've not yet come out with a version for the iTouch or java phones yet), and I personally think it to be pretty rad. The unfortunate part of it all is that only 1 person in the entirety of my address book has it installed. So essentially, I can see where I am at all times. Not so handy.
I'm not sure if the small following is due to a lack of awareness, or concerns over the privacy implications of having others know your whereabouts. I'm personally not overly concerned: I try to not go places I'd be embarassed about, and if I were to have to, say, go shopping at LuLu Lemon, I'd simply turn off the tracking feature. The accuracy seems a bit off as well (oh noes! Ypu can tell I'm within 4km of my house!) But I suppose there is a creepy stalkerish feel to it all.
I feel this is one more step forward in the technification of our lives. Location awareness fascinates me: I want my photos to know where they were taken, I want to know where I parked my car, and I want to track where I've traveled. Being cognizant of our time and place is not only cool, but also helpful: I see you're 2 towns over, I don't waste a phonecall asking you for coffee.
I'm sure there are more advancements in the workings, and I for one look forward to them!