A man walks along a common corridor of an old public housing estate flat in the Katong residential area built by the Housing and Development Board (HDB) in Singapore Feb 17, 2011. Around 85 per cent of Singaporeans live in HDB flats. [Photo/Agencies]

A man makes his way through snowdrifts in front of St. Isaac's Cathedral in St.Petersburg Feb 17, 2011. The temperature in Russia's second city fell to -20 C (-4 F) on Thursday. [Photo/Agencies]