I am looking for examples of web maps focusing on polar regions (Arctic or Antarctic) preferably using a polar projection.
What polar projection and tiling scheme could be used for such web mapping applications?
NASA's Operation IceBridge has a web map for its data portal hosted by NSIDC (National Snow & Ice Data Center). It has tabs to switch between northern and southern hemispheres.
This might not be a good example as it is pretty static and it's in Flash, but National Geographic has an interactive map here: Discover Antarctica
Sometimes all you need is a PDF: Antarctica Ice Velocity map (info)
The European Atlas of the Seas is another great example of geoportal centered on the arctic.