This question (or variations of this question) has been asked before, but as Apple's export compliance rules change relatively frequently, and no one seems to ever get a straight answer, I thought I would ask.
I write an iPhone application that uses version 0.2 of the Dropbox API.
I have emailed Apple concerning use of this specific API, and I will be sure to update this question as I learn more and hear back from Apple. In the meantime, if any developer is using the Dropbox API in their iPhone application, did you mark your application as using encryption?
Edit: Upon closer inspection, it looks like the file data is also transferred using SSL. Since their API is using the NSMutableURLRequest class over HTTPS though, I still can't determine whether or not this API "uses encryption." If in the App Store submission page I mark that it does include encryption, Apple then asks if I'm using greater than a 64-bit symmetric encryption key.