Despite its reputation as one of the world's most expensive cities, there are lots of things you can do in Tokyo for free:
A five-minute walk from the west entrance of Shinjuku Station, you can see as far as Fuji on a rare clear day from the 45th floor viewpoints at the Tokyo Metropolitan Government Offices. Back on the first floor, pick up a copy of the Tokyo Handy Guide from the Tokyo Information Centre for discount coupons to paid attractions.
The Tokyo Information Centre is also one of the best places to grab one of the city's free listings magazines (the best of which is Metropolis). You can also find free magazines in Tower Records, branches of HMV and the most popular foreigner hang-outs (Paddy Foley's, The Hub, etc).
When it's not in session, you can get a free tour of the Japanese parliament, the Diet. Call 55217445 to book.
Although most of Tokyo's best parks charge around 200 - 300 yen for admission, you can still visit the Imperial Palace East Gardens for free. Head to Yoyogi Park for weekend festivals, Japanese Elvis impersonators and the famous Harajuku Girls (Sundays only). Shrines and temples are always free - the best known are Senso-ji in Asakusa, Meiji-jingu (next to Harajuku JR) and Zojoji, on the edge of Roppongi. While you have to pay to get into its zoo or museums, there's always plenty of free entertainment in Ueno Park. Further out, you can easily spend a whole afternoon in Kichijoji's Inokashira Park.
Forget Akihabara and head to one of Tokyo's free showrooms for a view of cutting edge Japan. The Sony Showroom is in Ginza, while Toyota have a Mega Web in Odaiba (next to the Ferris wheel) and an Amlux next to Sunshine City in Ikebukero.
Don't miss the view of Shibuya Crossing from the Hachiko Exit of Shibuya Station. While the best bird's eye view is from the window of Starbucks, you can also look down on the street from the shopping mall between the JR station and the Keio Inokashira Station. Along with Ginza, Shibuya is also the best place for a bit of window shopping.
It gets mixed reviews nowadays, but an early morning visit to Tsukiji Market is still the best place to try fresh sushi.
Walk across Rainbow Bridge to Odaiba and watch the sunset from the island's artificial beach.
Take the train to Mount Takao or the Oku-Tama region for a day's hiking. On the way back, stop off in Fuchu for some free beer on the Suntory Brewery Tour.