Play Me I'm Yours at Museum of London (free entry) by JudyGR. Free piano practice available across the city now.
London that bit leaner.
Tonight: South East London Folklore Society meet for Mark Pilkington's talk, all welcome. Upstairs at the Old Kings Head, 8pm, £2.50.
Friday: The BBC Symphony Orchestra presents a World Cup-themed evening of free music-making at Westfield shopping centre ahead of the BBC Proms proper. 6.30-8pm, free.
Join Roam - the decommissioned mobile library-van-come gig space - in Haggerston Park for the Fence Collective’s Acoustic Picnic featuring Adem, The Pictish Trail and friends. 5-9pm behind the tennis courts.
The totally free and fun packed Hide&Seek Weekender at the National Theatre begins this evening.
Saturday: Early risers get with the beat in the Clore Ballroom at the Royal Festival Hall as Dare 2 Dance invites young female hip-hop groups to showcase their best moves and tricks and dance off against each other. 10.30am, free. Then witness the climax of Big Dance 2010 - the Big World Dance - which starts on the Southbank and boogies to Trafalgar Square. Register to take part and learn the routine here.
It's Lewisham People's Day in Mountsfield Park, Catford with Ska legends The Beat heading up an afternoon of music, circus, magic, art, sport and spoken word from over a thousand performers on eight themed stages. Plus a ferris wheel and funfair, crafts, real ale eats. Between midday and 8pm, free entry.
There'll definitely be something to entertain the kids with at Pleasance Islington's Big Day Out!
Nimble fingered folks and indie shopaholics need the Bust Summer Craftacular for "60 stalls of the hippest in handmade" at York Hall, Bethnal Green between midday and 7pm. £2 entry.
There's an afternoon fiesta on Valley Road Playing Fields, Curtis Field Road SW16 with music, food, crafts, guided walks and a treasure hunt through the woods. Noon till 4pm, free. Or you can join a guided walk exploring the wildlife, origins and heritage of Streatham Common at 2.30pm. Both part of Streatham Festival.
Sunday: Watch the World Cup Final live on the big screen in Walthamstow Town Square.
As a World Cup Final treat, leading Asian dance company Srishti present a fusion of football and dance, which brings the energy of Bharatanatyam to the beautiful game. 1pm and 2.30pm in Theatre Square, part of Watch This Space.
Free Bastille Day celebrations takeover Battersea Park all day.
Or walk Haringey's beautiful Parkland Walk with a nature expert between 11am-1pm. Meet Finsbury Park Cafe, free.
Visit Mayfield Lavender Farm near Mitcham. Free entry. Bring a picnic and sunscreen.
Monday: The Good Ship comedy club in Kilburn will doubtless be rammed for Josie Long's "Be Honourable" Edinburgh show preview. Support from Alexsis Dubos will start at 8pm but we suggest you get there well early. £4.
Tuesday: Opera comes to the big screen in Trafalgar Square from 7.30pm beaming live from the Royal Opera House in Covent Garden. Bring a blanket and some cushions plus a picnic for 3 hours of Simon Boccanegra starring Placido Domingo. Free.
Wednesday: Celebrate Bastille Day on Bankside listening to traditional accordian music outside La Cave restaurant Bank Chambers, Montague Place, 6-10 Borough High Street.
Catch the final night of Daniel Kitson's new Edinburgh show at the Invisible Dot, Camden Stables £2, 10.30pm.
Help keep London thrifty - let us know about cheap and free events happening in your hood. Email email@example.com, leave a comment or tweet us @londonist. And please do let us know if you follow up on our cheap suggestions - were they any good?