Not me.

However, I have had interest from family and friends to follow along on the trip. There are a few things I've learned however:

1. Be careful about the expectations you set for contact. For example, on a trip across Canada, I had my rear rim break. I was in nearby Laird River area with nice lodge and nearby hot springs, so I was fine. However, pay phone access didn't quite work to post my internet connections so folks didn't hear from me for eight days. Be careful in relying on some technology because if e.g. batteries are down or some other reason you aren't making contact - then you don't want folks to get unnecessarily worried because you set expectations that didn't include technology failure or lack of coverage somewhere.
2. Be careful on messages sent out, particularly if the issue might be transient. For example, in the moment a looming thundershower or mechanical issue might seem like the most important issue. If that goes into your update that way - you might resolve it fairly quickly but with limited contact it might still linger concerns far beyond that initial message, e.g. you might not even remember it was a concern by time you send a followup update.
3. Decide up front how much effort you want to put into providing updates - since you might find yourself doing it for the entire trip.

With that in mind, I haven't used a real-time SPOT type tracking update. I figure those are for bears, not for people .

What I have done, is use a periodic text message update (sometimes with GPS coordinates encoded) or a blog post or email post. On trip across Africa it was surprising how well cell phone network worked so I had ability to update blog with short "wordpress for Android" updates. I set expectations of "this is Africa, expect gaps of up to two weeks between contacts" and then ended up over-achieving with a more frequent short update.