I wrote about Palace Cycling around the Imperial Palace inTokyo before. Now share-cycle cogicogi offers service which is "borrow and return a bike anywhere you want."
自転車を貸出・返却できる「ポート」マップ。スタバも含まれていますね。
まだ渋谷・表参道周辺な感じですが、もっと大きいエリアに広がるといいですね。
It seems to be only around Shibuya and Omotesando area, but it'd be good if it'd cover more larger area.