Wikipetitions would be a Wiki for creating and forwarding petitions to the lawmakers of their respective countries(when permitted), administrative divisions, and even some of the local counties and cities, where anybody can edit the petitions. This collaboration may actually serve the purpose of changing the way we communicate with our lawmakers and elected-officials. Wikipetitions would also need a way for the petitions to be forwarded to said lawmakers, because a petition often has to be signed, but these petitions would actually be a collaborative effort to solve problems, rather than having to sign the said petitions. Since they will be articles, there needs to be a way to email or address the lawmakers.
Wikititions, Wiktitions, Wikicauses
I don't know, but I did host it here: https://commons.wikimedia.org/wiki/Commons:Village_pump/Proposals#Add_Editable_Petitions_To_The_Commons_Family