The Guardian, reports that Apple is poised to become America's largest public company. The paper said that the success of the iPhone and iPad have pushed Apple close to taking the top spot of the Standard & Poor's 500 from oil company Exxon based on market capitalisation.

This milestone has been reached because of the incredible volume of sales of the iPhone 4 and the iPad that have increased the company's revenue dramatically. According to analysts, who have forecasted that another 5 million iPads, and 12 million more iPhone 4s have been sold since its release in June. Revenues are forecast to be $19bn for the quarter and $5bn of profit, and as reported earlier this week, Apple's share price is expected to rise even higher than $300.

This turnaround for the company, once struggling in the early nineties, is said to be down to the vision of Steve Jobs. After being fired from the company in 1985, Jobs rejoined Apple in 1997, and from then on the company, though operating through some difficult market times, has now not only surpassed Dell in value, but earlier this year overtook Microsoft in market capitalisation. Apple is now third, behind Dell and HP, in the US personal computer market. However, it's the success of Apple's new products, iTunes, iPods, iPhones, and now the iPad, that has shot its value up so dramatically.

Since Jobs rejoined Apple, he streamlined the company, and then refocused his developers on customer experience, and in the process, turned Apple's fortunes around in a major way. Launched in April, analysts think that the iPad could sell up to 25million units in 2011 due to the growth in the tablet market. Also, if Apple does hit the top many of Exxon's existing investors may switch allegiance to shift billions of their dollars to Apple, pushing Exxon's value even further down.

If Apple were to finally beat the oil company to the top slot it will share it with General Electric, General Motors, and AT&T. The Motley Fool is now weighing up the pros and cons of whether you should now invest in Apple or Google shares.