Red Sea crossing
The nation of Israel had been enslaved in Egypt for four hundred years, but was now were being led by God eastward toward the land of Canaan. God had chosen to avoid leading them directly into Canaan through Philistine territory because he did not want them to be intimidated when they experienced war (Ex. 13:17), and instead had chosen to lead them on a more round-about path through the desert toward the Red Sea. While from a political standpoint this might have been judged to be a savvy move, initially this did not appear to be the best move militarily (from a strictly human point of view). The nation of Israel found itself encamped "before Pi-hahiroth, between Migdol and the sea", in a seemingly vulnerable position.
Pharaoh had decided to pursue the Israelites, and at the sight of the approaching army the Israelites and began to panic. After Moses sought God regarding the situation, God stood blocked the advance of the advancing army and sent a "strong east wind" all night that caused the sea to divide in two. The Israelites walked across the now-dry Red Sea, making it safely to the other side.
The Egyptian army attempted to accomplish the same feat, but God "looked down upon them" and interfered with their advance. Realizing that God was fighting against them, the Egyptian army began to retreat. God caused the waters to recede, however, drowning the army of Pharaoh.
Thus, God showed himself glorious by apprehending his enemies in a trap that they had intended to use to trap his own people.
In addition to the account left in the biblical record, the crossing of the Red Sea is attested to by the Jewish historian Josephus in his work Antiquities of the Jews (II: 15-16). Josephus claims that he is relaying the account he found in the "sacred books," and urges his readers not to doubt the account. Josephus's account appears to differ from the biblical account in some aspects (e.g. the waters were parted by Moses striking them instead of by God making use of a strong east wind).
Controversy regarding the site of the crossing
The Biblical record states that the nation of Israel "went up from the land of Egypt prepared for battle." After making it clear that God opted to avoid the direct route through Philistine country, Exodus 13 states that the Israelites "journeyed from Sukkoth and camped in Etham, on the edge of the desert." Exodus 14 begins with God commanding Moses to encamp at a specific location right on the Red Sea:
“Tell the Israelites that they must turn and camp before Pi-hahiroth, between Migdol and the sea; you are to camp by the sea before Baal Zephon opposite it. Pharaoh will think regarding the Israelites, ‘They are wandering around confused in the land – 'the desert has closed in on them.’ (NET Bible).
Josephus provides some clues regarding the geographic location of the crossing:
...God commanded him to bring the people to Mount Sinai, that there they might offer him sacrifices. Now when the Egyptians had overtaken the Hebrews, they... drove them into a narrow place.... They also seized on the passages by which they imagined the Hebrews might fly, shutting them up (29) between inaccessible precipices and the sea; for there was [on each side] a [ridge of] mountains that terminated at the sea, which were impassable by reason of their roughness, and obstructed their flight; wherefore they there pressed upon the Hebrews with their army, where [the ridges of] the mountains were closed with the sea; which army they placed at the chops of the mountains, that so they might deprive them of any passage into the plain. (Jewish Antiquities, Book II: 15:3) 
Some scholars have argued that the Reed Sea, rather than the Red Sea, was the site of the Red Sea crossing, and that the Egyptian army was drowned by an incoming tide.
Other scholars believe in a literal crossing of the Red Sea. Some have asserted that this would have taken place at the Suez Canal branch of the sea. But still others argue that the Gulf of Aqaba farther to the east was the site of the crossing. In 2001 The Exodus Revealed: Searching for the Red Sea Crossing was released on DVD, in which scholars made the case for an literal Red Sea crossing at the Gulf of Aqaba. According to this theory, the Israelites followed Egyptian trade roads across the what is now known as the Sinai Peninsula. Here they encamped by the sea at the beachhead proceeding from the peninsula, across the sea from Mount Sinai on the other side of the gulf. The channel separating this beachhead from the opposite site was more shallow than were other parts of the Gulf, and roads lead to it through the hills, concurring with Josephus' description. Perhaps the most significant finding was the presence of chariot-wheel shaped coral formations in the waters between the beachhead and the other side (click here  to view a satellite image of the proposed site of the crossing).
A number of films portray the Red Sea Crossing:
- Humorously portrayed in Mel Brooks's History of the World: Part I (1981) 
Scripture Quotations are taken from the NET Bible: http://net.bible.org.
- "Pharaoh's chariots found in Red Sea? 'Physical evidence' of ancient Exodus prompting new look at Old Testament'." WorldNetDaily. http://www.wnd.com/news/article.asp?ARTICLE_ID=33168
- "The Red Sea or the Reed Sea?" The Good News. http://www.gnmagazine.org/issues/gn10/redsea_archaeology.htm