Gambling is one of this country's most popular activities. In 1996, Americans made $586 billion in legal bets. One expert estimates that 4 million people in this country are addicted to gambling. 48 Hours takes a look at this pastime, profiling a recovering gambling addict, a woman whose obsession with scratch-off games has left her deeply in debt, and a cabby who trades online while he drives. Melanie Morgan was a successful radio and TV journalist. Then she started playing poker, in legal games in Seattle. Soon she let everything else go, including her career, her marriage, and even her newborn baby. Correspondent Troy Roberts reports on her long struggle to regain control. A recent study found that 70 percent of day traders lose money. But Kenny Glick is convinced that he can buck those odds. Correspondent Susan Spencer reports on an activity that many critics say is just another form of gambling. Scratch-off lottery tickets are enormously popular in Massachusetts; by one estimate the state makes $800 million from this game. But this form of gambling has its price. Among those in its thrall are Terri Candido of Boston, who is more than $50,000 in debt. Correspondent Harold Dow reports. While he is ferrying fares around New York, cabbie Carlos Rubino, who has a laptop computer in his taxi, trades online and even offers tips. Dow reports from Manhattan's hectic streets.