There are now instructions for using the library's Proxy Server Bookmarklet with an iPhone.
The original Proxy Server Bookmarklet allows you to save a bookmark into your browser that will take any web page and send it through the library's proxy server. If you click from Google Scholar or some other site into a journal or database to which your affiliation with the University of Michigan Library gives you access, but which doesn't recognize you as being from U-M, you can use the bookmark to reload the web page through a library server, giving you access.
Now, this same bookmark is available for iPhone users. See the MLibrary Proxy This Bookmarklet for iPhone for details and instructions (it takes one additional step to set up the bookmark on your iPhone, compared with desktop- or laptop-based browsers).