I dropped out of the process when a company asked me to get a reference from my current manager... for a job I had not yet left. I responded quizically and they amended it to "we'd make a conditional offer". I said I was uncomfortable leaving a job where I had (as I would hope most do) some guilt about putting them in a challenging position, wanting to keep a strong personal relationship and then saying "Hey, can you be a reference for my new (i.e. better) gig?" They couldn't udnerstand this perspective, so no thanks!