Is there a way to retain a map with as much detail as possible (street view, maps, directions, zoom levels) offline?
This question refers to the Apple maps program that shipped with iOS versions 1 to 5 that relied on google map tiles. Please open a new question for iOS 6 maps and the google map app that is also available on the App Store since 2012.
Without jailbreaking, the iPhone DOES cache the last few map tiles on the view, at all the view zoom levels. I'm not sure how extensive this is, and because it's only a temporary cache the data is always a second away from deletion.
Without jailbreaking, you can download an application, there are lots of them, but my favorite is called MotionX GPS, which is on the App Store. It allows you to cache and save certain types of map tiles from a variety of map modes, including Terrain, roads, and more. I'm not sure if they're specifically Google Maps, but you can get some types of maps for sure.
After jailbreaking, which is both legal and easy, you can find a couple of 3rd party utilities to help you download map tiles to the device, but most of them require you to view the tiles in the app itself, not in the Maps application.
Yes there is, but to do it properly requires a jailbreak (legal, voids warranty) and a possible breaking of the Google Maps TOS.
The cache can be used to an extent: The Google Maps application uses its cache offline, so tiles are visible and the map can be panned a bit (if it was panned while online and could fetch neighboring tiles). Directions are retained in the list view even if you can't follow them all in map view.
If you want more than this, it isn't built in by default. If you jailbreak, you could hack it to have a much larger cache that supports hundreds of MB of content including zoom levels, etc.
Setting it up would be a significant hack and against the Google Maps TOS. When online, you'd need to sniff your own packets off the iPhone, detect those involving Google Maps, and build a cache. When offline, you'll want to redirect all requests to Google Maps servers to a local HTTP server running on the iPhone, and then serve the tiles.
I've seen this done with a computer that was frequently offline, but not with an iPhone, but it should work just fine. You can also add custom tile layers this way if you want.
Another method does not involve as much hacking. It seems some people have already solved this problem. You do need to jailbreak, and directions will not work, but browsing at different zoom levels should work, and GPS works too, so you at least know where you are.
See the following sites:
I use CityMaps2Go for offline maps. Not quite the same as Google Maps, but pretty good for my use. I live in a relatively low-population area, so there wasn't a map available for my area at first, but they added it within a few days of my requesting it.
The application Atomic Web Browser can save a static copy of a Google Map page locally. The saved page cannot be scrolled or zoomed, but it is available offline. I tested with Airplane Mode on version 4.0.2.
This may not satisfy all of the criteria, but there are a handful of humongous (in terms of file size) applications that have map data stored locally. Think traditional GPSes with screens that have to have this data stored locally.
XROAD, Inc. has US West and US East apps that offer navigation features, and have map data stored in the application, so you may look them up offline, manually, or online with automatic triangulation. Note that these ARE NOT Google Maps. Per mankoff, Google's TOS prevents any other company from offering turn-by-turn on their map data (less current agreements with Apple and the like).
iTunes App Links:
There is very likely more if you look around, these are just the two that I've been shown before should I ever need to travel in a place with uncertain coverage.
The iOS map app will cache tiles for as long as it can. In practice, my iPad will cache tiles for a turn by turn trip across the country and generally not lose any of the tiles when playing light games, reading books, etc... It's not foolproof, but the less you do with the device, the longer your tiles stay in memory.
Google's tiles are not generally licensed for offline use. They do have an excellent static map API that might suit your needs but you'll have to find another app that allows more control over pre-loading map tiles for true offline use. The iOS map app simply doesn't do what you ask.
I recommend OpenMaps - which uses OpenStreetMaps for map data. Simple to use, you can download the needed map area at any or all zoom levels.
Browse the maps of OpenStreetMap, download them for offline use, edit the maps (tag editing and node creation), find out where you are, search for addresses, get directions and scan the map for tweets with OpenMaps for iPhone, iPad an iPod touch.
For offline maps, I use Offmaps, the old version. The map display is much faster than of City Maps 2Go, and my personal opinion is that it also feels much more like a iOS app should feel like. So even though Offmaps has no working compass, cost more money, can’t download in the background and I had downloaded CityMaps for free, I stick with Offmaps.
(Developer Felix Lamouroux has released a rather misleadingly-named new version some time ago, which is a different thing altogether — more a city guide with Points of Interest and maps.)
I've installed on ipad galileo-offline-maps, and it keeps available previously opened maps when offline.
As others have noted, you can't easily do it with Google Maps on a standard handset. What you can do is use another source of maps. There are a number of apps that use OpenStreetMap that allow you to download maps in advance. The one I used, oMaps, downloads data a different levels of detail so you can zoom in and out.
The maps are a little variable in quality but undoubtedly better than having no map at all.
I use the GaiaGPS App for my walks. This is free and does the job. You can save maps and use them once you're on the spot without any connexions. And you can zoom! No need to say that this don't cover Street View, because of the size needed for this kind of feature.
