I'll bite.
a.) Cost-saving tips for travel & lodging
I applied only to schools that were nearby (no further than a 4 or 5 hour bus ride) -- not to save money, but because I wanted to stay in the Northeast. That being said, it obviously did save money on travel. For flying in general, I recommend kayak.com (which searches all of your favorite travel sites and airline sites directly = cheapest tickets) and farecast.com (which will keep track of low prices over time and will predict whether the lowest cost for your search criteria will go up or down -- good for timing your purchasing). Obviously, it helps to try and schedule interviews in the same city/state/region for one trip.
For lodging, I would stay with a student host whenever it is offered. You save money on a room
and you get to hear about the school from a student
and you'll likely be closer to campus than a hotel. If the school doesn't offer hosts, I suppose you could ask (I never tried this, but it wouldn't hurt). Alternatively, you can find a friend or relative who's in the city you applied to. Start asking your parents for email addresses and phone numbers of long-lost relatives.
I liked to schedule away interviews on Monday or Friday so that I could visit that city for the weekend. If you like to take occasional weekend trips anyways, this would, in a way, save money because you wouldn't need to go back for vacation purposes. Plus, it's a more enjoyable way of going through this long and stressful process.
b.) What you wear
I'm a guy, so I wore a suit. I was going to buy a new suit for this occasion, but I couldn't find anything affordable, so I just used my all-purpose black suit from high school that was starting to get a bit small for me. I don't like wearing white shirt with a black suit, so I wore either a blue or gray shirt with a tie that matched well.
c.) What the "routine" questions are
Most of the interview questions were about me and my application (definitely go over your AMCAS and secondary before each school so you know what they know about you.)
"Tell me about yourself"
"Tell me about activity X"
"Tell me about Y on your application."
and then these were just starting points for conversations. Interviewers have different styles, and you have to adjust. Some of them are rapid-fire (though not necessarily tough questions); some are more personable. An interview with a personable interviewer might seem like a "good" one, while one with a colder interviewer might seem like it didn't go well at all, but there's no correlation with acceptance, in my and my friends' experiences. In any case, just go with the flow, be friendly and don't ramble (try and get a feel for how long they expect you to be talking -- if they cut you off, for instance).
d.) What the "unusual" questions are
Hmm.. One interviewer asked me to explain the C on my transcript in one of my major classes.
I explained that I thought I learned the material well but didn't perform well on the exams (not good at multiple choice). then why did you do so well on the MCAT?
I practiced a lot. Then why so horribly on the written section (N)?
:: I think I said something to effect of being disappointed with my score, and maybe something about how I like to put a lot of thought into writing and am not the best at writing in short time frame. Take home point: I made sure not to whine about being a couple percentage points from a B.
Other questions: what are the biggest challenges we are facing in healthcare? I can't remember anything else really. Perhaps 2011ers will have a fresher memory. But to be honest, I didn't get many hard questions.
e.) "Horror stories" about your worst interview moments
f.) ...how you handled the above missteps.
Hmm.. I didn't really have horror stories. I had really bad traffic one day for my Howard interview coming in from my relatives' place in the 'burbs of Virginia (first the car wouldn't start, then the number of disabled vehicles and other crazy traffic incidents (for instance, a prisoner escaped out of a prison by hiding underneath a bus and holding on. He ended up getting fatally hit by a car or something). Anyways, I showed up late (called in car to say that I was running really late) and it turned out to be fine because they have this first-come first-serve thing. so I had the last interview of the day.
Other things about interviews.
Morning or afternoon interviews. Some schools will give you a choice. Morning interviews mean you get it over with; afternoon interviews mean you get to hear about the school through the info session/tour/etc before the interview. I preferred afternoon interviews personally.
Other interview formats? All of my interviews were one-on-one. I think I had one student interview (as a second interview at that school). Perhaps other Allo students can address team interviews, and whatever else is out there.
"Do you have any questions?" After taking afternoon interviews and being bombarded with information and the "do you have any questions?" question, many interviewers understand if you don't have any questions. Many people recommend having something to ask, but I've gotten into schools without asking a question per se. Sometimes I'll ask vague, stupid questions if I feel I need to (if the interview was not at all a conversation), like "What do you find most special about this place?"), or if the interviewer had an unusual specialty (like nuclear medicine) or a higher up position, you could ask about that specialty, department, line of work or whatever. Successful people often like to talk about themselves. Look interested and perhaps have a couple follow up questions.
I hope I didn't talk about the obvious too much, but hopefully this is a good starting point for the discussion. Let me know if there are questions or disagreements!