For further info, here are some good links to check out:
An excellent place to start are the Tokyo episodes of Anthony Bourdain's No Reservations and Parts Unknown. They're available on iTunes for a few bucks, and even if you don't much like Bourdain, the episodes will provide you with some great things to do and places to go.
Tokyo Art Beat: http://www.tokyoartbeat.com/
By the way, Tokyo Art Beat has an iPhone app. It's $2 and worth it because it has maps of all the venues so you can find your way.
Tokyo Metropolitan Museum Of Photography: http://syabi.com/e/contents/index.html
National Museum Of Modern Art: http://www.momat.go.jp/english/
Tokyo Wonder Site: http://www.tokyo-ws.org/english/
Time Out Tokyo: http://www.timeout.jp/en/tokyo
Go Tokyo: http://www.gotokyo.org/eventlist/en/list
Reddit Tokyo: http://www.reddit.com/r/Tokyo/
Reddit JapanTravel: http://www.reddit.com/r/JapanTravel/
Tokyo Damage Report's Punk Rock Tour Guide: http://www.hellodamage.com/top/tokyo-tour-guide/
Tokyo Gig Guide: http://www.tokyogigguide.com/
If you plan a night out drinking, make sure to search for recent postings on "Roppongi scams." Even in this very safe city, bad things can happen.
Also, search for "Tokyo monk scam." You'll see the so-called monks in the touristy areas, offering cheap stickers in exchange for "donations." Just say no.
Questions? Feel free to contact me directly: firstname.lastname@example.org