The melting clock in Salvador Dali's The Persistence of Memory is a familiar icon.  One can purchase analog and digital versions of these clocks, hand-crafted by artists, but it is also possible to create one at home by recycling an old vinyl LP and following a series of simple directions...

Step 2: Preheat your oven to 220F/100C and toss in the record for a couple minutes. When it's thoroughly flopping about, yank it out and run to a table to do the next step.  Run! It hardens quickly!

Full directions are at Instructables, via Anything and Everything.