The Utterly Butterly Ukulele project (TUBUP) runs around Great Britain helping people make their own ukulele from recyclable materials--in this case, margarine tubs. TUBUP puts on workshops in which the ukes are constructed and attendees learn how to play it and take part in a live performance.
The ukuleles are constructed from an Utterly Butterly spread tub, fishing line strings, a piece of wood with screw eyes for tuning pegs.
Here's a great photo gallery from a recent fundraising event in Cardiff, Wales in support of the BBC Children in Need program.
The folks behind the Utterly Butterly brand seem to be pretty cool. For several years, they even had their own formation wing-walking team!
Here's TUBUP's site.