I've started going on the occasional business trip again, and my husband came up with a great way to keep me involved with what's going on at home — he's twittering regular updates on what he and my daughter are doing, and I'm getting them piped to my phone. It's a neat way to stay involved (and keep worrying — "oh, no, it's 9:30 and she's not asleep yet!?!").
We also use twitter for "ambient intimacy" with my sister who lives outside of Istanbul — it's a great tool for families to keep up with one another.
You can set up protected Twitter accounts that aren't visible to everyone — only the people you allow in. Good for this purpose.
Related: Use Twitter as a baby-album-of-sorts