The Robo-One tournament in Tokyo is scheduled for this weekend - March 19th/20th at the National Museum of Emerging Science and Innovation (Miraikan). The event takes place in the big hall on the first floor of the museum.
I plan on attending the finals on Sunday, and will try to post a review and photos on this site sometime next week.
For those of you that can't make it in person, they will be doing a live broadcast of the event via the internet on Sunday (Japan time.) The netcast is scheduled to start at 10:30 am, Sunday morning. You can check it out here: http://robo-one.tv.ibee.ne.jp/live/
The link is already up and functional, but isn't broadcasting yet. It appears to be an embedded Windows Media Player, which makes sense since Microsoft is one of the main sponsors of the event. There is no indication whether or not they will archive the netbroadcast for later viewing, so I have to assume that they won't.
The competition schedule shows events from 11:00 am right on through to 4:30 pm. As far as lunch is concerned, there's a Wendy's near the front of the museum - other than that, you're on your own. I would suggest eating before you come, then packing a candy bar or something else to munch on so that you don't miss out on any of the fun.