That might be workable - I'll have to talk to our server guy - however again, I think this would be a great option if you are able to implement it, as it would greatly improve the professionalism of the system for companies that are run by more than one person, such as our own. I noticed you said that if a feature "isn't currently a feature in PhotoPost PHP Pro, we can more than likely add it in a matter of days." - surely this would be an ideal feature that can only benefit the users, and thus yourselves? I admit I'm not too intelligent when it comes to coding stuff up but I think that this shouldn't be a massive change in the way PhotoPost works.
If it would indeed take a lot of time then I understand - as I said, I'm not too smart on that sort of thing, that's more Samuraid's (our server guy) specialty.