Actually now I wondering.  It looks like GPLv3 is not compatible with the iPhone (the anti-Tivo clause: <a href="http://www.fsf.org/blogs/community/why-free-software-and-apples-iphone-dont-mix" rel="nofollow">http://www.fsf.org/blogs/community/why-free-software-and-app...</a> ) but I am less clear if GPLv2 is incompatible (or if people just hope it is, see: <a href="http://www.geoffeg.org/wordpress/2009/10/07/the-iphone-and-the-gpl-v2-are-not-incompatible/" rel="nofollow">http://www.geoffeg.org/wordpress/2009/10/07/the-iphone-and-t...</a> ).  So you may want to look a bit deeper into the license of the library you are using (LGPL, GPLv2, GPLv3 ...).