I usually countered FizzBuzz question with an offer to show of the source code of a small project I wrote while studying. While some didn't care, most interviewers were actually happy about it and let me do it. I tell them about the problems I had and how I approached them, usually leading to a question from me on how the company had similar problems and how they solve them. In my experience this "opens up" the interviewer(s) to talk a bit more honestly about development practices in the company.

On test projects. I generally expect that companies (after a pre screening) put similar efforts in me as I put in them. If you let me do a two day project, I'd expect that one person (preferable my future boss or a future colleague) to show me a "company fitting" solution and take the time to discus my work and theirs. If you're not willing to spend that time I'll most likely think you don't respect my time. Which is a factor in choosing a company. I understand you are busy, I hope you understand that I’m too.

Edit: not a native speaker, sorry for bad english