Genesis 11 is plain silly.
God is worried that these ant-like humans will somehow become omnipotent if they can build a tower that reaches to heavens? This God is paranoid. Doesn't he understand the laws of science, that humans could never build something to reach heaven -- they'd eventually die from the lack of oxygen or their building would tumble over.
And they weren't building it just to be out of reach of a flood, because God (short-sightedly) promised to never bring such a flood ever again.
Verse 7 says that languages were created instantaneously by God. (I'm borrowing an objection from www.skepticsannotatedbible.com here, but I think it's really valid.) Linguistic studies have shown that languages evolved gradually over long periods of time. By long, I mean even longer than 4,300 years (the length of time it's been since the Noachian Flood allegedly occurred).