How SHOULD you make (and use) static libraries on the iPhone

Question

AFAICS, any serious iPhone developer must make and use static libs on a regular basis, or else condemn themselves to buggy, hard-to-maintain, unwieldy projects. But

Answer 1

Something I missed out, because I haven't included any categories in my own static libs:

You MUST include the linker flag "-ObjC" if you use categories, or else your static lib will be "missing" some bits and pieces when you try to use it in projects.

I have heard of people placing this flag in 6 different places, but the one that seemed to work for me was:

In library project (not app project, strangely), go to build settings, and add a user-defined setting:

OTHER_CFLAGS = -DObjC

...although I believe it ought to be instead:

Other Linker Flags = -ObjC

(NB: this has the side effect of setting the OTHER_CFLAGS automagically inside the GUI)

Also, I've heard a lot of people claim it should go in the application project, but they were all embedding their projects together, not compiling true static libs, so I suspect they just got lucky.

ALSO ...

XCode / Iphone OS 3.0 seems to have a bug where you also need the -all_load flag (use exactly as with the -ObjC flag above). There's some StackOverflow questions about the use of -all_load flag with 3.0, so have a look at them for more info - I'm not really experienced with that.