Practical issues of achieving this goal aside, just what is a god anyway? In an article in rec.arts.sf.science, John Schilling proposed a basic taxonomy of three classes of godhood:
A Type I God can do anything within the framework of physical law. Although this sets strict limits to a god's powers, it's still a nifty level of ability to possess.
A Type II God can rewrite physical law at will. If you postulate a creator for our universe, or if you already worry about escaping the Big Crunch/Heat Death, this is what you are dealing with. The possible existence of such entities is speculative.
A Type III God would not be subject to the laws of mathematics and logic. It could maintain an irresistible force and an immovable object at the same time. Obviously, this kind of entity is highly speculative.
Personally, I don't intend to ponder too much the possibility of Type II and III gods until we have reached Type I godhood.