I am definitely open to and intrigued by the possibility that aliens created or at the very least contributed to the engineering of humans and human civilization.It would make more sense to ask
Creationist: Is it possible for aliens to exists?
Evolutionist: Yes!
C: Is it possible for them to exist in a form different than us?
E: Yes!
C: Is it possible for it to exist in a radical sense, unlike any sense here on earth? Consciousness that exist purely in energy form only, for example?
E: Yes!
C: Is it possible that they may have abilities, that here on earth would seem super human? Telepathy for example?
E: Yes!
C: With our one technology advancing even to the point of cloning animals, is it possible for an alien race to be so advanced that it could create life?
E: Yes!
C: How about matter then? Is it possible they could create whole worlds possible if they were advanced enough?
E: Yes!
C: Destroy worlds?
E: Yes!
C: So its possible for an alien race to have all of these qualities at once?
E: Yes!
C: So an Invisible alien, with the ability to read minds, create worlds and people on it, that also has the ability to destroy the world it created and populated, could exist somewhere, right? Its possible?
E: Yes!
C: Can God exist?
E: Of course not, don't be silly.
=D
As the late Arthur Clarke stated, "Any sufficiently advanced technology is indistinguishable from magic."
I'd like to add though that even with this sort of stuff I'm an "agnostic" - I'm not into the sort of pseudoscientific stuff spouted by the likes of (the late) Zecharia Sitchin.