Shibuya has been attracting few internet companies to the area like Amazon.co.jp, Ask.jp (Japanese version of Ask Jeeves), Become.jp (partially owned by Transcosmos just like Ask.jp (their offices kick seven shades of bantha pudoo out of the Amazon.jp offices)) , Yesasia.com, Technorati.jp and Google. Not sure if there's a particular reason why these companies are gathered in Shibuya but I hear that office space is not that expensive considering the great location.
Apart from being home to some of the coolest internet sites, Shibuya is also a great place to go shopping. there's two large Bic Camera stores to buy your electronic gooodies but if you dont like the sales assistants (because they dont know what they're talking about) then you can always go to the Sakuraya in Center Gai (to find more sales assistants who dont know what they're talking about).
There's also a ton of restaurants - Italian, Indian, Chinese, French, Endorian - you name it they have it. Make sure you drop by Shibuya when you are over here instead of spending all your time and money in Akihabara ^^.