I've set up a mediawiki's and phpBB boards for various people, so whilst I don't have a GPS, I'd be happy to help with wiki maintance, after exams (and after I know what I'm doing next year) I'll likely have a look at the code for the various editors and see if anyone would like assistance. I've done projects in C# and Java, and just made the mapping tool in JS, PHP and mySQL, so know that quite well.
I found out about this after Mapchester, but I might come along to the next one!
I'm based in Manchester until the end of June.
A admin needs to edit http://wiki.openstreetmap.org/index.php/MediaWiki:Sidebar . See also MediaWiki talk:Sidebar