Renga is an ancient form of japanese writing that created the haiku. Basically a poet would write a haiku (3 line poem with the first line having 5 syllables, second having 7 of them and third having 5) and deliver it to another poet.
The second poet would write another mini-poem composed of two lines, each with 7 syllables. Then the second poet would deliver the whole poem to another poet which would add to the poem a haiku, and so on...
And this is how I hope this will work, not necessarily different poets all the time but the same pattern. Unlike other stuff like the first line poetry though instead of writing a different poem you add to the main poem, thus creating a grand poem made by more than on artist.
I think I shall start:
when slugs come out for rain I feel very un-comfortable for snow's not dancing