Where is a good place to place Category in Obj-c?
<p>I've addeda category to NSString. I've tried to place the code in my appDelegate.h and it works. However, I've tried placing it in another .h file that I included from .pch file so that this category can be used project wide. However I kept getting the following error:</p>

<pre><code>ld: duplicate symbol .objc_category_name_NSString_StringTrim in ....AppDelegate.o and .....main.o
collect2: ld returned 1 exit status
</code></pre>

<p>The weird thing is, I only get this error when I compile for the simulator but not device! Any ideas?</p>
