Friday: Dance at the free Afrocuban Jazz Brasilian & Tropical Beats party downstairs at the Vortex, Dalston from 10pm-2am.
Saturday: Get free Olympic Triathlon action a year early at the 2012 test event and World Championship series meeting in Hyde Park (and Sunday).
It's seasidey on the Southbank all weekend with a beach regatta and other fun stuff.
Join a free Mural Walk from Surrey Quays to Deptford, meeting at Canada Water tube at 1pm and end up at a pub in Deptford around 3pm.
Hook up with the Charles Fort birthday saunter at 4pm outside his former home on Marchmont Street then crawl round pubs that spell out his name. NB this might not be cheap if you decide to throw yourself into buying drinks part of the pub crawl.
Sunday: Join a free guided walk in Lee Country Park looking out for water voles! Meet 10.30am Old Mill and Meadows Car Park) off Station Road, Broxbourne, EN10 6LX. Walk lasts approximately 2 hours.
Hackney One Carnival processes from Ridley Road market starting at noon, along Church Street to Clissold Park, where it shacks up for an afternoon of community fun including London Wildlife Trust's green picnic.
Brixton Splash is a free community street festival celebrating all things SW9 from noon till 7pm in Coldharbour Lane, Atlantic Road, Electric Avenue, Windrush Square and Peace Gardens.
Monday: Drop by the National Theatre and see the free Press Photographers Year exhibition. Some of the photos will take your breath away, some will make you laugh - all will make you wonder where on earth the last year went. Open till 11pm.
Tuesday: Get to spoken word night Utter! at Green Note, Parkway, Camden before 7.30pm and get in for a fiver for a night focused on puppets.
Wednesday: OK, OK - this is £6 a ticket so strictly speaking not 'cheap' by our definition of a fiver or under but it's a night of folk music in the Urban Physic Garden which sounds ace!
Thursday: Let SELFS take you on a botany folkore walk through Burgess Park with a trustee of South London Botanical Institute, 7pm, £2.50. Bargain.
Hungamunga and their Musicarium bring adult crafty fun to the Baby Bathhouse, 125 Church Street, Stoke Newington N16 from 6-11pm, free entry.