Question: Is there a way to have an app write a into a file and then have another app read from that file?

I mean writting into the file system of the iPhone.

I want to do this without using an internet connection. So uploading the file and then downloading from the other app is not what i mean.

Thanks!

Answer: 
The current sand boxing of applications does not allow this, however it appears that this may be available in future iPhone OS versions. [Reference](http://www.techhail.com/gadgets/iphone-os-3-2-for-ipad-with-improved-text-file-document-support-xcode-tools/3088)
I'm not sure exactly what circumstances you're in here, but you could register app B as a handler for a particular protocol, and have app A try to open such a link (e.g. appB://yourinfohere). It depends on how much data you want to transfer and many other things, but it might work.