Because of the architecture of jQuery Offline, you can call $.retrieveJSON whether or not the user is online, and the plugin will either make an immediate request or kick off a request when the user comes back online. This also means you can kick off a timer for a request for new content in the callback to jQuery.retrieveJSON.
It seems like I’ve already written about a lot of lightbox plugins, but Lightbox_me (Apache License, Version 2.0) is a relatively small and useful addition to the collection. It adds events to handle window resizes, and has a very small DOM footprint, unlike many lightbox solutions which can be quite heavy.
I’ve had to write a cut-down Google Maps style map interface before, and it’s not trivial. Mapbox (MIT License) would have been a good alternative: it can show multiple layers of content, supports mousewheel zoom, and has a simple API and DOM requirements.
Although Google Maps is great, there are times when a real map isn’t required or a particular project’s licensing or legal requirements prohibit Google Maps. It’s worth keeping projects like this in your bookmarks for just such occasions.