For me, I'd use it for recording calls. I'm also interested in what the mod community comes up with - there's usually a lot of innovation in the JB space that Apple cribs into big iOS updates.
Can you record calls with a jailbreak? Last time I checked (which would have been around iOS 5, I think) it was not possible, as the baseband handled the audio for calls and it never touched the main OS. Several jailbreak apps claimed to be able to do it, but on further investigation they all worked by forwarding your calls through their own phone number and recording on their end, which is pretty awful.
