Those of us covering the campaign got an e-mail from Obama communications strategist Robert Gibbs a little after 3 this morning saying Obama had landed in Afghanistan. The timing of the trip had previously been shrouded in secrecy for obvious security reasons. But, in retrospect, I probably should have put it together (as I'm sure many of my more observant colleagues did). A little over a week ago, a Netroots Nation spokesperson told me the campaign had told her Obama was going to be out of the country during the conference, which was scheduled to run from Thursday through Sunday. Then, this week, the press was reporting that Obama would be in Jordan and Israel beginning Monday before heading to Europe later in the week. And we already knew Obama was headed to Afghanistan and Iraq at some point. That left a two-plus-day window in which he'd be out of the country before he was due in Jordan. Which basically had Afghanistan and Iraq written all over it if you were paying attention.
I'm not sure what the point is here other than that it's incredibly hard to keep a trip like this secret from someone who's really trying to figure it out. Then again, my sense is that the people who handle security for these things don't expect to keep them completely under wraps till the very moment they happen. Just vague enough for long enough to dampen (rather than completely eliminate) any potential threat.
As for the first leg of the trip itself, the Times has a useful report here.