I do something similar: “Are there any last minute concerns or questions that I can address now?”
Incidentally, that one question in an on-campus interview just may be what got me the job I currently have lined up. I was doing a panel interview, and one interviewer that was silent the entire interview up to that point spoke up when I asked that question. He asked me some questions about my interests that weren’t covered in the rest of the interview, and when I went to the onsite the next week he mentioned that my answers to those interest questions were what made them feel I’d be a good fit for the team, and likewise what secured me an invitation to the on-site interview.
Though with this one you need to gauge the interviewer, and it’s usually easier to do that in person. I had one friend use this question at the end of an interview that didn’t go so well, and the interviewer responded along the lines of “Why? Is there something I should be concerned about?” If you’re not prepared for a potential response like that, I’d avoid this question. I only pull it out if I feel that the interview went fairly well, and have gotten some good responses to it even if I didn’t end up getting an offer.
Another good set of questions I like to ask: “Is there anything you think a new hire should know about working at [insert company]?” and “In your opinion, what is the best thing about working at [insert company]?”.
The answers to these can be very revealing, particularly if you get the opportunity to ask them to multiple interviewers individually. If you can ask multiple people, you’ll tend to start noticing some patterns to the answers that give you a very good idea of what it’s actually like working there, or at least the most prominent aspects. And if you can ask people individually, they tend to be more honest in mentioning any negatives because they don’t have the pressure of their coworkers/potentially boss right there.
As far as general phone interview advice, smile while you’re talking. That naturally perks up your voice. I used to be terrible at talking on the phone until I had to do multiple phone interviews and learned that trick to not sounding totally monotone on the phone. Also, if you can try to dress up in interview clothes before the call. At the very least try to put on a button down and maybe some dress pants. For me at least, it reminds me that this is a formal call and gets me in the right mindset.
Keep in mind that as much as they’re interviewing you, you’re also interviewing them. They’re trying to determine if you’re a fit for the position and team, while you’re trying to determine if this is the right opportunity for you. So on that note, while you want to stay formal you also don’t want to act completely differently than you normally do. If your personality doesn’t fit with the company culture, it’s probably not the best opportunity for you. Better to determine now that it’s not a fit than to fake your personality through the interview process and realize on the job that it’s not a fit.
Good luck!