This excellent site covers, virtually, all the sights of Oslo. Navigate your way around the Norwegian capital via the Interactive Map, and take the Grand Tour slide-show of what to see and where to go. The 'what to see' section is limited to a big ski-jump(Holmenkollen), a park(Vigeland) and a bunch of museums(over 50), so make sure to stroll around the rest of the city via this remarkable map tool. Simply click on an area of the city, choose a street, and you'll see the view in all directions.
From the more well-known sites such as Akershus Castle, to random roundabouts and street corners, you will begin to get the feeling that you're actually there(a sensation that's embellished by stunning 3D panoramic pictures). Though lacking the cultural diversity of somewhere like London or New York ; Norway does have leafy streets and a generally unfazed approach to life that will be endearing to even the most trenchant of travellers.