Unlike Will, I never read sites like TechCrunch. Too corporate in outlook; and not enough taste. It isn't a filter, it is a firehose. I prefer to pick up news from blogs by more discriminating humans, like John Gruber's Daring Fireball. Anyhow, here are two things DF led me to today:
let's take a look at Meebo as if we were desktop application developers. If you load up Firefox and go to google.com, it takes up about 40MB of memory. If you sign into GMail, it uses about 50MB. Take your browser over to meebo.com and sign into AIM, that's 61MB. Have a conversation with a friend? 69MB. Chat for a while with said friend? You're up to 79MB. That's right: if you use Meebo for a while, it will use 39MB of memory over Firefox's base usage. Gaim, by comparison, uses 15MB consistently, when signed into Google Talk and chatting all day.
Realistically, cheap laptops for kids will need the efficiency of free desktop applications, not web apps uber alles.
Tumblr is a host for very low threshold, easy, but structured blogs. If I hadn't recently moved my base of operations to Blogger, I'd be tempted to try a Tumblr.