Here’s a quick and dirty way of accessing the subway map on your iPhone.
Safari to the MTA’s Subway Map:
http://www.mta.info/nyct/maps/submap.htm
Save as a bookmark, and you’re done.
Remember that you’ll have to load it up prior to using the subway as you’ll lose connectivity. Just load up the page, then open a new browser window so you can keep the map cached.
I’ve found that browsing the map was even easier by stripping out the the MTA’s top banner and navigation bar on the left. So I saved the map (which are 2 gif files), and created a webpage that loaded just the gifs. I then placed it on my server which I can use whenever I want. I’d make the link public, but the map is probably copyrighted, so you should make one for yourself.
Say goodbye to paper subway maps forever!