I would say that I'm pretty far behind the curve on 'gettting' this social media tool, but as it's still in private beta, I guess the fact that I'm on it at all makes me still technically ahead of the curve. Of course I refer to FriendFeed, one of the many lifestreaming utilities out there. Now that I've had several months to play around on it and be in the private testing pool, I can say that as of the last few weeks, it's finding it's way more and more into my regular concentric surfing circle.
When you say lifestreaming tools, a number of sites come to mind. Twitter might be among them, though it clearly has other applications aside from lifestreaming. Tumblr is most certainly chief amongst them, though it comes at lifestreaming with a clearly artistic and bloggish approach. Then there are the variants of the bigger ones: Jaiku and Pownce. All of them have a common thread: you hook all the RSS feeds you generate on a daily basis into their system, and organize them (or not, depending on the system) into one long RSS feed for public or semi-public consumption.
FriendFeed, though, is the odd man out, or so it would seem. Aside from Tumblr, the rest have a chat-like or IM-like quality to them. Tumblr itself is more appealing to the bloggers, I'd imagine. FriendFeed is a lifestreaming service, I've decided, that is most likely to appeal to those who head to forums for their online entertainment.
Unlike Twitter, what goes on behind the login screen at FriendFeed isn't indexed by Google or publicly discoverable, either, so a lot of the comments get a much more 'behind-the-scenes' raw and uncut feel to it. While some of that takes place on Twitter, it happens a lot more on FriendFeed, in my experience. And much like how Twitter is analogous to an IRC channel where you select which people you see writing, FriendFeed is something like a private forum where only people you subscribe posts you can see.