GIVE BLOOD: Donate some of your life fluid today at Lambeth Town Hall (Brixton), Conway Hall (Holborn) or Brewers Hall (City). Free, just turn up, all day
PANTO: Two of the first pantomimes of the season get underway today. Check out Dick Whittington Goes Bollywood at Tara Arts (not based on actual events) and The Comatose Beauty at Royal Vauxhall Tavern.
GET A TINY BLACKBOARD: An odd but wonderful event takes place in Tower Hill City car park (betwix the DLR and Tube stations) today where Joan of Art will be giving away miniature easels decorated with happy messages. If you're passing by, go say hello from us. Free, just turn up, 10am
SAMPLE SALE: We hear there's a Nicholas Kirkwood Sample Sale for shoe lovers at Mercer Street Studios. Fancy shoes from £50. Free, just turn up, 10am-8pm
SCULPTURE: See models and mock-ups of previous and future Fourth Plinth sculptures, in a new show at the ICA. Runs until 20 January 2013. Free, just turn up, 11am-11pm
LIGHT: Carolin Crawford speaks at the Museum of London, in a Gresham Lecture, about the manyatmospheric effects we can enjoy when light from the sun and moon interacts with constituents of the atmosphere. Free, just turn up, 1pm
OLDSTERS TENNIS: See stars of yesteryear, such as John McEnroe, Pat Cash and Tim Henman thrash it out at the Royal Albert Hall in this year's Statoil Masters Tennis tournament. It runs from today till 9 December with various times and prices.
AGEING: How does what we eat affect how we age? Bring your sandwiches to Wellcome Collection’s lunchtime talk. Free, just turn up, 1pm
LITERATURE: War Horse author Michael Murpurgo talks about his life and work, and reads a new autobiographical short story at the National Theatre. £4, prebook, 6pm
CHARITY CAROLS: ChildLine and the NSPCC hold a carol concert in Christ Church Spitalfields, with several A-list celebrities in attendance. Join Sir Michael Caine, Sir David Frost, Baroness Floella Benjamin and HRH The Countess of Wessex for some charitable carolling. We even hear that Caine will be reading from A Christmas Carol, reprising his role from The Muppets' Christmas Carol! £25 including refreshments, £10 (students), £75 (VIP), prebook or on-the-door, 6.30pm
MORE CHARITY CAROLS: Alternatively, head to the gorgeous St Bartholomew's The Great in Smithfield for a candlelit concert for Mencap. Notables in attendance include Sebastian Faulks and Patricia Hodge. £40, prebook, 6.30pm
CLIMATE CHANGE: Visit the Dana Centre in South Kensington for an update on climate change and the possible ways to mitigate its effects. Free, prebook, 7pm
GIG: Catch a free Patrick Wolf gig at Rough Trade East. Turn up during the day to buy his new album and you'll receive a wristband for the gig. Any left over will be given out free at 6pm. Free, just turn up, gig at 7pm
UKE FLASHMOB: Turn up to Trafalgar Square to witness a monumental gathering of ukelele players, who are flashmobbing like it's 2009. If you'd like to join in, see the instructions here and register. Free, just turn up, 7.23pm
BELIEF: A 5×15 event at Wellcome Collection sees five commentators with views on belief take it in turns to interview each other. Good panel, too. Free, prebook, 7.30pm
WASSAIL: Cecil Sharp House in Camden puts on a A Feast of Songs & Wassails with traditional a capella ditties. £5, prebook, 8pm
Random London Fact of the Day
We couldn't find any figures for the distance round the perimeter of London, so we measured it in mapping software. You'd have to walk 138 miles to completely circumnavigate Greater London, following all the boundary twists. To put that in context, you could get to Sheffield, Brecon in Wales or even the outskirts of Brugge for the same distance from Charing Cross. By a strange quirk of numerology, it's also 138 miles from the centre of London to the centre of Grimsby, home town of Matt, your humble editor and Random London Fact compiler.
Winter really starts to bite, like a rancourous terrier with icicles for teeth. Temperatures plummet, like said terrier following an unfortunate cliff-top 'accident'. Yet at lunchtime, the sun shines, like the same terrier somehow managing to fuse hydrogen nuclei into helium for the sake of keeping the stupid analogies coming. The BBC has a less confusing weather report.
Secret Hidden False Rumour Of The Day
An ancient bylaw requires the London Borough of Sutton to be entirely free of interest and news. It very occasionally breaks this law.