NZ Referendums is a site aimed at encouraging use of the Citizens Initiated Referenda Act 1993. The Act is theoretically a powerful tool for letting politicians know what we think, but a high threshold (you need the signatures of 10% of eligible voters, or around 200,000 people) and hostility from MPs has seen only three referenda voted on since it was passed. The website aims to change that by providing a platform for people to float broad ideas for a topic and gain an idea of support, hash out the exact wording in preperation for a formal referendum proposal, and then use the network of supporters to collect signatures.
Given the threshold involved, I'm not sure that this will really be an effective tool (OTOH, it's a tool, which is a lot better than we have at the moment). However, it strikes me that such a site would be perfect for organising petitions to Parliament. These have similar co-ordination issues to referenda, but without the intimidating threshold, and are IMHO a much more useful method of feedback. Hopefully the site will be upgraded to allow this - or else I suppose someone else could always set one up...
(Hat tip: Holden Republic)