I don't know why, but I found myself contemplating this one morning as I was trying to wake up.
The inaugural question: Can God (supposing His traditional existence) make an object so big even He cannot lift it?
The answer: Yes.
While God is good at making things, he isn't actually all that strong.
Yes, because of the word "lift". Lift generally implies moving something away from a center of gravity. Without an external gravitational source, "lift" becomes meaningless. Once the object is large enough that its gravity is the primary attractor in a region, "lifting" it doesn't really make sense any more.
If an object is made that is larger than Earth, but still is orbiting the Sun, "lifting" it would essentially mean applying more angular momentum to push into a more distant orbit. However, this isn't really "lifting". In addition, once the object has broken free of the Sun's gravitational field, you are no-longer even "lifting" it in that sense. If an object is our sun, which was ostensibly created by God (given the existence of God), then "lifting" it already has no real meaning. Lifting it in relation to what? There isn't really any "up" as far as it is concerned. Therefore, not only can God create such an object, He has already done so many times.
The real question here concerns the inherent absurdity of an "all-powerful being". If someone can do anything, he or she can do many contradictary things. Of course, this is frequently extended to an almost Zen-like answer. For example: God can create an object so large that He cannot lift it, but of course, he can lift it. Since the being can do anything it can also logically not do anything as not doing something is also doing something. Being unable to lift a chair is a way a being could limit itself, since it is "all powerful" it could limit itself in this way as well.
Discussions of what an "All Powerful" being can thus go nowhere as there are no limitations, even in the creation of limitations. The very notion is absurd.