CLEAN THE THAMES: If you're near the southern tip of the Isle of Dogs with a spare morning ahead of you, why not help Thames21 clean the foreshore of plastic bags and other detritus? Free, just turn up, 9am-noon
CHILDREN'S BOOKS: The RNIB Literary Wonderland opens next to Southwark Cathedral. Hear celebrities read extracts from children's books while sat under giant mushrooms. Free, just turn up, 9am-6pm
FIREFIGHTER OLYMPICS: Watch our beleaguered fire-fighters compete in various lifesaving challenges at the World Rescue Challenge at ExCel. There's also an exhibition and talks. Free, but book in advance, 9am-5pm
SNEAKERS O'TOOLE: An exhibition of sporty footwear begins today in Covent Garden Piazza. Just like going into a shoe shop, but with more tourists. Free, just turn up, 9am-7pm
LOST PRINCE: We almost had a Henry IX. Instead we got the doomed Charles I. The National Portrait Gallery's new exhibition, which starts today, looks at the life and death of this lost prince. Runs till 13 January 2013. £11.80, from 10am
MACHINES AND ART: The Futurefield Gallery within Finsbury Park has a new exhibition merging art and technology. See videos from virtual worlds, inter-species digital psychogeography, and projected creatures who shy away from torchlight. Runs till 5 December. Free, just turn up, 1-5pm
LIGHT SHOW: A new light installation is unveiled beneath Hungerford Bridge this evening. 21st Century Light Space Modulator hangs from the south-eastern end of the bridge and responds to movements of passers-by. The opening will be marked by a performance by Akademi, a south Asian dance group. Free, just turn up, 6.15pm
VETS OPEN HOUSE: A chance to poke around the Royal Veterinary College in Camden, with RVC Late. Scientists will be on hand to guide you through veterinary medicine, plus anatomy talks, a bar, and the chance to handle a (fake) pregnant cow. Free, just turn up, 6.45-10pm
SPEED LISTENING: Bring your portable music player along to the White Horse (Hoxton Street) and share your favourite tracks with other punters, then listen to theirs. £5, 7.30pm
LATE OPENINGS: The National Portrait Gallery and Wellcome Collection stay open until 9pm and 10pm respectively.
Random London Insight Of The Day
You'd think a building was a pretty solid, immovable thing. Not a bit of it. London's structures are a pretty mobile bunch. The decamping of the Crystal Palace from Hyde Park to Sydenham and the shifting of London Bridge to Arizona are just two examples. See many more examples (and perhaps suggest some additions) on our map of London's peripatetic buildings.
Change, so they say, is inevitable...except from vending machines. And also from London's weather, a constant cinerious mantle of cloud with little chance of sunshine. Or so BBC Weather tells us.
Secret Hidden False Rumour Of The Day
London is named after Iron Age comedy double-act Lonnie and Donnie, who wowed the pre-Roman nomadic population with hilarious skits on the dangers of not washing woad from your hands before going to the toilet, and the time Cassivellaunus got his beard caught in a spindle.