what preconceptions students have about your course material
Not a "first five minutes" thing necessarily, but polling is a good way of activating prior knowledge. Prior to the first meeting, I often poll students (using Google Forms or PollEv) on what they've read.
If students’ prior knowledge is faulty
Could get sticky with colleagues. "Foucault WHAT?! Who told you THAT?!..."
That way, every student has the opportunity to answer the question, practice memory retrieval from the previous session, or surface their prior knowledge — and not just the students most likely to raise their hands in class.
I've seen folks do this with index cards: I think the small form factor and disposability emphasizes the spontaneity and makes students more likely to overcome anxiety. I would also add that this exercise is particularly good for introverted and/or insecure students: I think it feels easier to read something than to speak it, for many students.
But instead of offering a capsule review to students, why not ask them to offer one back to you?
Twofer, I like it: a) cognitive psyche-based emphasis on repetition after an interval to cement the memory and b) emphasis on student-centered ethos, on the student becoming the master of what goes down in class.
At the end, he returns to the questions so that students can both see some potential answers and understand that they have learned something that day.
I like that, especially since the students will have forgotten about the questions by the end in many cases. But will I remember to bring them back?!
the first five minutes of a college class often get frittered away with logistical tasks
I think my teaching notes template actually says "fritter away five minutes" on the first bullet point under the heading.