Last night I made a phone-post but I think I mistyped my caller-id and/or PIN and managed to hit someone else's journal instead. I don't know where it went, but it said it was posted successfully and yet it is not in my journal today.
I think it would be useful if the phone gateway quickly spelled out the name of the journal associated with the callerid and PIN you entered so that you can see if you got the right one. Of course, this does have a major security implication: if you do mistype and manage to hit someone's journal, you then know whose journal you've got access to which might cause malicious people to cancel their current phonepost but make a note of what they typed in for later abusing.
While on the subject, I'd also like to optionally have the phone gateway tell me what it thinks my callerid is when I press the “pound” key to auto-login, since despite trying several combinations I still haven't found what LJ is seeing as my callerid when I call from a British number through my unofficial 0870 (national rate) access number. If I didn't have to type the callerid in every time there'd be less chance that I'd get it wrong in the first place.