We finally moved the open community guide to London (previously known as grubstreet) from UseModWiki over to OpenGuides. Wow. It only took just under a year from deciding to rewrite UseModWiki in maintainable Perl to coming up with a complete specialised city guide application.
There are three Open Guides online now:
More info is available at the OpenGuides website - if your city doesn't have an Open Guide then why not set one up? It will work right out of the box for any UK city (after you configure it, of course). For cities in other countries, all the features should work fine apart from the location stuff — offers of assistance in sorting that would be greatly appreciated.