Dave's question is not a new one; it's been around since the church in the second century when a controversy arose about the divinity of Christ. The early church struggled with the notion of Jesus' birth and the pre-existence of Christ. This discussion eventually led to the formalizing of the Trinity doctrine that was adopted in the fourth century.
Before we delve into the question at hand, a quick overview of the Trinity might be helpful. The Trinitarian formula states the God is three-in-one: God the Creator (or Father/parent), God the Son (Christ), and God the Spirit. Three entities, but the three are one in the same. It's a complicated formulation, but it has 1,600 years of traditional acceptance.
The Bible itself has no specific doctrine of the Trinity, rather the belief comes from a compilation of Bible verses. One of the best examples of these verses is found in John: "And I will ask the Father, and he will give you another Advocate [the Holy Spirit], to be with you forever" (John 14.16). Here is where we see a plurality of the GodheadChrist speaks of praying to God the Father to send the Spirit, thus we see three distinct entities. As to the unity of the Godhead, this is seen variously in scripture, but is characterized by Christ's assertion, "I and the Father are one" (John 10.30).
But what of the pre-existence of Christ? Did Christ exist before he was earthly born? The traditional answer to that question is, "Of course." Scripture plainly states that Christ existed before his earthly ministry.
The first passage supporting this notion is found in John's prologue to his gospel, "[Christ] was in the beginning with God. All things came into being through him, and without him not one thing came into being" (John 1.2-3), then "he" is identified in verse 14 as Christ. Further, the wording of the creation account in Genesis 1 has traditionally been used to assert Christ existed in the beginning, "Then God said, 'Let us make humankind in our image, according to our likeness'" (Genesis 1.26). Tradition has long asserted that the word "us" supports the doctrine of the Trinity, since who else could God be talking to?
Of late, however, the doctrine of the Trinity has fallen on hard times. Scholars and ministers alike have de-emphasized the doctrine, professing at best skepticism at the concept. These assert that the full-blown doctrine of the Trinity as expressed in Church tradition is just thattradition without implicit Biblical support. This de-emphasis does not detract from the divinity of Christ (nor necessarily the pre-existence), nor from the doctrine of the Spirit of God. Instead it holds to the mystery of God as three entities who are of the same "substance" (so to speak), but are individually distinct.
Is there biblical support for this notion as well? The answer is yes. One prime example is found in Philippians: "Christ Jesus, who, though he was in the form of God, did not regard equality with God as something to be exploited, but emptied himself, taking the form of a slave, being born in human likeness. And he humbled himself and became obedient to the point of deatheven death on a cross. Therefore God highly exalted him and gave him the name that is above every name, so that at the name of Jesus every knee should bend, in heaven and on earth and under the earth" (Philippians 2.5-10). Here we see a definite subordination of Christ to God; an assertion the Christ is not the same as God.
So, did the Trinity exist before Christ Jesus was born? Tradition resounds with a hearty, "Yes", but scripture isn't as confident. However, when the question is reworded as, "Did Christ exist from the beginning?" the answer returned is, "Yes, scripture heartily supports this teaching." So yes, David, it can be said that Christ was present at the creation of the world.