good bar food /street vendor food

I will be traveling to Japan sometime in April. I am planing to stay around the Ginza area i am looking for place to go at night to enjoy good bar food or street vendor food. for example tempura or octupus ball. any help is greatly apprecicate.

Hi!
I searched "tempura" and "octopus ball" by Google maps.

These are tempura restrants near Ginza.
http://maps.google.com/?hl=en&ie=UTF8&z=4&om=1&layer=c

and these are takoyaki(you call "octpus ball") venders near Ginza.
http://maps.google.com/?hl=en&ie=UTF8&z=4&om=1&layer=c
It is "C" marked that we call "Gindako".
"Gindako" is popular takoyaki vender company in Japan.
They have a lot of takoyaki shopes in Japan and another asia countries.
http://www.hotland.co.jp/english/
It is yummy:)

You will sea "What is TAKOYAKI?" pages in Gindako's page.
http://www.hotland.co.jp/english/wthas-tako.html#what-tako

Ameyoko near Okachimachi station - about 5 stops from Yurakucho (the JR station nearest to Ginza) has a vibrant atmosphere and takoyaki.

Scroll down on this and you'll see a picture.
http://ponkanchan.blogspot.com/2010/03/okachimachi.html

Street vendor food isn't as common in Tokyo as you might think in, and you definitely won't see any in the very upmarket Ginza area! Not far away though is Yurakucho station, and there are dozens of "hole in the wall" yakitori places under the tracks, especially going south towards Shimbashi station. These are permanent shops rather than stalls.

While there are a few street vendors which set up at night in some areas of Tokyo, you only see large numbers of them at festivals and special occasions like at shrines at New Year, or in parks during cherry blossom season- it's different from the situation in Bangkok or India for example where there are street vendors lining roads all the time.