To add FLTK projects as a new project template for Xcode 3, install the 
included files in the directory 

> cp -R ide/Xcode3.1/Project\ Templates/FLTK/* \
    ~/Library/Application\ Support/Developer/Shared/Xcode/Project\ Templates/FLTK\ Application/FLTK/

and restart Xcode.

The generated projects expects fltk 1.3 as it is installed
using the command line.

> sudo make install

Enjoy!

 -  Matthias

Please send me an EMail if you find errors or would like to suggest
improvement: mm@matthiasm.com