DropVox is a clever and highly specialized application that, quite effectively, turns your iOS device into a voice recorder with Dropbox-based storage.
Install the app, launch it, hit the record button, and your recording is uploaded to your Dropbox account in .m4a format as soon as you’re finished creating it.
You can also configure DropVox to start recording immediately after launch and to continue recording if the device is locked or other applications are in use.
Hit up the link to grab a copy. DropVox is currently $0.99 (50% off for a limited time) and works on the iPhone, iPad, and iPod Touch with microphone attached.