Twenty years ago today, a British advertising executive came up with the concept of Blue Monday, the day considered to be the gloomiest of the year. According to a clever calculation combining meteorology, motivation, finances and the need for change, the third Monday in January is the one when we most need to get away from it all, since this concept was invented to promote the merits of a travel agency. So, short of a ticket to Tahiti, this week's selection offers enough artistic escapism to keep us dreaming until the sun comes out. Don't worry, be happy...