As I said I'm not the first to recognise this and the parties are working hard to exploit it, so I thought I'd do a short look into their setups.
First the Lib Dems
It's a fairly standard list of campaigns with links and thumbnails, nothing special really (I can't say I rate the general Lib Dem site much, to busy and difficult to navigate, particularly in terms of policy. Click on the link on the left and it offers you a hundred different places to go for different purposes and results, just needs simplifying heavily). Then you need to go through secondary links to open PDFs to find the info. The banners on the right easily available to add on the sidebar of blogs are the best part and the only really good idea within it.
Second the Conservatives
Same basic idea as the Lib Dem one, just much better presented (as the site is in general, particularly the policy section, an easily available summary on a simple web page with an in-depth link. The social networking links are a major plus since as I've said I think these'll come to be major driving forces in organisation.) The 'What you can do' section within each campaign section is a good idea if slightly limited.
Lastly, Labour. Also LabourSpace
I kept it until last because (despite all the criticism Labour's web efforts get) I think it's the best and most interesting of the three. The Labourspace seems to reverse the focus of party campaigns. Rather than them being official party campaigns and inviting people to support it. The structure is for campaigns to be started easily and people to try and recruit supporters, with the most popular ones being brought to the attention of party bigwigs and possibly taken on as official party policy.
The caveat to this is that I've no knowledge of how it works in practice and how much far up popular campaigns can go. Ed Miliband appears to be on there a fair bit, make of that what you will. But whatever the practicalities the concept at least is interesting, a more direct form of how parties can potentially become more grass roots influenced as I mentioned in my last post (namely if there are pre-existing factions looking to use them as tools to achieve their aims)