Objective evidence for the existence of Jesus Christ?

[watchamadoodle]

This is what I would propose as criteria for a "historical Jesus":

A demonstration that there is enough independently verified information and criteria about "jesus" that it is reasonable to conclude it would be likely only to apply to a single historical person.

If the information we have about jesus could reasonably be expected to apply to, say, 500 people alive at that time, then we don't have a historical jesus, in my opinion. We're pinning a story on any one of a bunch of random guys, or more likely, a combination of many characters. If it can be so easily shifted like this, then personally I say historical Jesus has not met its burden of proof. If it's fair to assume jesus is a mixture of more than one person, then this is not good enough.

Rob, I agree with your definition of a historical Jesus. Here is a quote from wikipedia:

Virtually all scholars who write on the subject accept that Jesus existed, although scholars differ about the beliefs and teachings of Jesus as well as the accuracy of the accounts of his life, and the only two events subject to "almost universal assent" are that Jesus was baptized by John the Baptist and was crucified by the order of the Roman Prefect Pontius Pilate.

http://en.wikipedia.org/wiki/Historical_Jesus

I would add a third implicit belief that scholars would accept about Jesus - he was a leader in the group that became the early Christians in Jerusalem.

That is enough detail to meet your criteria for a historical person IMO.