Shares of iPhone maker Apple Inc. (AAPL) reached an all-time high of $325.72 on Wednesday's regular trading session, after it said shipments of the second-generation version of Apple TV to exceed 1 million units this week.

Apple stock finished Wednesday up 0.29 percent at $325.16 with an average volume of 17.71 million shares. In the pre-market hours Thursday, Apple shares were trading down 0.05 percent to $325.00 on the NASDAQ stock market.

Apple's market cap hit $298.27 billion on Wednesday, leaving it ahead of rival Microsoft Corp. (MSFT), which has market cap of $241.16 billion, as the largest technology company in the world and second largest company in market capitalization.

In September, Apple overtook PetroChina Co. (PTR) to become the world's second largest company by market value. However, it still has to go a long way to surpass Exxon Mobil Corp. (XOM) in the market capitalization where oil giant retains the top spot with a whooping $367.10 billion.

On the other hand, Apple's price-to-earnings (P/E) ratio of 21.46 is ahead of software giant Microsoft's 12.15, and Exxon's 12.89. P/E ratio is a valuation ratio of a company's current share price compared to its per-share earnings over the last twelve months.

In general, a high P/E suggests that investors are expecting higher earnings growth in the future compared to companies with a lower P/E. The P/E is sometimes referred to as the multiple, because it shows how much investors are willing to pay per dollar of earnings.

On October 13, Apple shares blew past the $300-mark for the first time in the company's history on the back of growing popularity of the iPhone 4, the iPod and especially the iPad.

Jobs Doing Job For Apple

Apple's success has been largely credited to its co-founder Steve Jobs, who was named the world's best performing CEO last year, according to January 2010 issue of Harvard Business Review.

Recently, the U.S. President Barack Obama during a speech on Wednesday referred to Steve Jobs as an example of the American dream and one whose wealth should be celebrated, according to Cnet.

On Dec. 23, British international business paper the Financial Times named Steve Jobs as its Person of the Year this week.

Jobs also recently made in to Forbes magazine's annual list of the wealthiest Americans, climbing to 42nd place with net worth of $6.1 billion as on September 2010.

Insanely creative Apple co-founder transforms multibillion-dollar industry every few years. First, personal computers with Apple II, Macintosh; then film with Pixar; music (iTunes), mobile (iPhone). Now iPad is treated as messiah tablet, savior for publishing industry. Apple still sells computers, but twice as much revenue now comes from music distribution and hand-held devices, Forbes stated in the profile of Steve Jobs.

Apple TV -- A Game Changer in TV Space

We believe the Apple TV is now positioned to become a more material contributor and game changer in the TV space. But we believe a major catalyst for the set-top box would be the addition of an App Store, allowing users to download new applications for the Apple TV, said Shaw Wu, an analyst at Kaufman Bros said in a report to clients.

While the new Apple TV has definitely generated greater consumer interest, it is still too small to really impact estimates. We view the Apple TV as part of AAPL's longer-term living room ambitions, of which its new North Carolina data center is also a part, said Peter Misek, an analyst at Jefferies in a note to clients.

Apple releaesd the second-generation version of Apple TV on September 1, 2010. The new Apple TV offers the simplest way to watch your favorite HD movies and TV shows, stream content from Netflix, YouTube, Flickr and MobileMe, for just $99. iTunes users are now renting and purchasing over 400,000 TV episodes and over 150,000 movies per day.

Apple TV has Apple's A4 (ARM Cortex-A8) chip processor and graphics processing of PowerVR SGX535 with a memory of 256 MB. The new version has no hard drive; however, it does have 8 gigabytes of flash storage for caching purposes. All content is drawn from online or locally connected sources.

The latest TV has connectivity port for Micro-USB, HDMI, infrared receiver, and optical audio with networking capacity of Wi-Fi (802.11a/b/g/n), 10/100 Ethernet. About a quarter of the size and one-third of the price of the original Apple TV, the new device can stream rented content from iTunes and video from computers or iOS devices via AirPlay.

The second generation Apple TV runs a version of iOS (known as iPhone OS prior to June 2010), rather than the modified Mac OS X of the previous model. The interface is similar to that of the previous generation, with only slight modifications. The second generation sold 250,000 units in the first two weeks it was available.

Apple's operating system iOS 4.2.1 was released on November 22 with support for all Apple A4 devices, 3rd, and 2nd generation devices, with the exclusion of the Apple TV. It brings initial support of iOS 4.x to iPad, plus AirPlay and AirPrint to all compatible devices. It also contains minor changes to the YouTube app and alters the multitasking animation.

On December 14, Apple released a new version of Apple TV (version 4.1.1), with features such as enhanced TV resolution. As the second generation Apple TV is iOS based, developers have used the traditional Jailbreaking techniques to install additional software on the Apple TV.

Apple on Wednesday updated its Remote application for iOS devices, adding the ability to remotely stream a video from a computer's iTunes library to the new Apple TV via AirPlay. Remote version 2.1 (iTunes link) is now available on the App Store as a free download. It is compatible with the iPhone, iPod touch and iPad, and requires iOS 3.1.2 or later.

Notable competitors of Apple TV include Western Digital Media Center, Roku, and Google TV.