Both templates in downloadable .pdf here:
here (the triangle)
here (the slot box)
I think what these templates suggest is that creating the planters is not a very hard thing to do.
The geometry is exceedingly simple (the easiest one being a triangle) and all you really need is an exacto knife(i like Olfa the best--that's the extent of my marketing schill...).
So really, posting the planter templates is showing the real potential of the urban environment and the simplicity of a good 'urban hack.'
If you've developed your own awesome shapes and what not, give us a shout (firstname.lastname@example.org) and we'll post them up! Do remember, though, that we interpret this project as part of a larger theme of "ideas for the city" rather than a "designer object"(as in don't be a marketing dick and use it to make a quick buck...more on this later) so everything that gets posted to the site will be considered 'non-commercial and remixable' a la the creative commons licence found here.