Well i have just discovered this for myself, so i figured i would right up a *bit* of a tutorial for it.
i have not got my iphone yet, so i cant exactly tell you how to get it ON there.... but i can get the process rolling.
first of all. the programs you will need are:
MapThis! - this is WINDOWS ONLY unfortunately. this downloads the maps, as you specify, from google maps online
Maps offline - iphone app, reloads/saves your cache of maps
these programs can both be found here:
Maps Offline MapsOffline4iPhone
maps offline requires Jiggy app on your iphone as well.
found here:
MapThis! requires .net framework 2.0
here:
Microsoft Download Center
DOWNLOADING THE MAPS
ok, first of all, you need to make sure you have .net framework installed.
the .exe file for MapThis! is located in GMDL/bin/debug
its still in early development and its slightly difficult for screens UNDER a resolution of about 1280x1024
you will notice the google maps page loads with lots of random buttons and boxes around the outside.
ultimately, all you really need to know is "Download the map" and "set dir" up the top
so type in the location you want. and then move the map around, zoom in, zoom out, whatever you want to do.
what is displayed is exactly what will get downloaded. dont worry about zoom for now.
once you have the outskirts of your 'custom' downloaded map lined up.
you need to type a name for it. (up the top, to the left of "set dir")
for example "_melbourne" you MUST put in the underscore (for some reason)
after that, press "Download the map".
something will pop up with all of the tiles that make up the map you framed earlier.
this is where the zoom comes into it.
you have the option to uncheck the tiles you dont want as high detail images. (i.e. zoomed in)
once you have unchecked the ones you want, then you can click the big long button up the top.
it will start to download the map. the progress is shown up in the top left corner.
wait for that to finish.
then click on -> iphone up the top.
fairly straightforward options... not much reason to change anything i dont think.
but this is where i stop. i cant go any further.
it will make a folder called iphone_map (default is on the desktop)
a lot of information was taken from touchpodium:
View Google Maps Locally With Maps Offline 0.1 | Touch Podium
i give anyone permission to modify this, or elaborate on it, or tell me how it goes, or write up the second half of actually INSTALLING IT onto the iphone to add onto this.
ultimately. please let me know how it goes. i live in Darwin and the map ended up being 55mb.... for the WHOLE city (which is um... actually smaller than Ballarat). not too shabby
let me know how it goes. i just got an update saying my iphone wont be here til about the 5th of may 
