How to show related city name according to the incoming call on iPhone?
<p>I want to add something (eg. the related city name) into the UI view when I make a phone call or received a phone call on iPhone. However, I can't figure out a good solution for this idea. Could anyone who has experience on this subject gives me some suggestions?</p>

<p>My currently solution is, try to write an extension based on mobile substrate and hook functions in SpringBoard. So many difficulties existed and following are my current big questions,</p>

<ol>
<li><p>How to develop such a extension? I downloaded some examples from google, unfortunately they cann't even be compiled on my toolchain.</p></li>
<li><p>I can't figure out which ui view for the related screen I should use to insert my own component. I get header files of SpringBoard via class-dump, but no docs and no comments about its usage. Could someone share his discoveries with me?</p></li>
<li><p>How to build a trusted cross-compiling enviroment on leopard? All kinds of confusing errors pop up when I try to build others's codes. I've tried Zdziarski's instrunctions in his book, it works with iPhone OS 1 and can compile common projects with open sdk, but how should I do to make it works when comipiling ms plugins?</p></li>
</ol>

<p>Also, is there any other solution to translate my ideas to codes? I start iPhone development one month ago, no experience with cocoa/Obj-C before. So your suggestions are very appriciated.</p>

<p>~ Link Bian (卞林扣)
Email/MSN: linkou.bian@gmail.com</p>
