Apple on Tuesday refreshed the iMac and Mac Mini in time for the holiday-shopping season, adding a 27-inch screen to the all-in-one desktop and adding Snow Leopard Server as an option for Apple's lowest-priced desktop.

In addition, Apple introduced a wireless mouse that uses the same multi-touch technology found in the iPhone, and started offering a redesigned MacBook, the company's lowest-priced notebook.

The upgrades came a day after Apple reported that Mac and iPhone sales drove stellar earnings for the third quarter of the calendar year. Profits soared to $1.67 billion and revenue rose nearly $2 billion.

In an attempt to keep the momentum going, the company's latest refresh beefs up processor speed and graphics performance while maintaining the same price as older models.

The latest iMacs include an LED-backlit, high-definition display with a 178-degree viewing angle. The 27-inch model features a 2560-by-1440 pixel screen offering 60% more pixels than the previous 24-inch model, which has been dropped along with the old 20-inch version. Apple now offers a 21.5-inch iMac, along with the 27-inch model.

The smaller iMac starts at $1,199 with a 3.06 GHz Intel Core 2 Duo processor, 4 GB of memory, a 500 GB hard drive and a Nvidia GeForce 9400M graphics processor. The 27-inch model starts at $1,699 with the same processor and system memory as the smaller version, but with a 1 TB hard drive and an ATI Radeon HD 4670 graphics chip with 256 MB of cache.

Upgrading the processor to a 2.66 GHz Intel Core i5 quad-core ups the price to $1,999, which includes a better graphics processor, the ATI Radeon HD 4850 with 512 MB. The 27-inch iMac also include a video-in port, to allow using the system as an external monitor in a few years, when the rest of the machine is obsolete.

The Mac Mini desktop, which starts at $599, is now available for $999 with Snow Leopard Server, a 2.53 GHz Intel Core 2 Duo processor, 4 GB of memory, dual 500 GB hard drives and a Nvidia GeForce 9400M graphics processor. The server edition makes it possible for a small business or home to use the Mac Mini to share calendars, address books, files and multimedia across a network.

The new wireless Magic Mouse comes with the new iMacs and is available separately for $69. Rather than use mechanical buttons or scroll wheels for navigation, the top of the mouse is multi-touch surface that enables the use of gestures to scroll through long documents, pan across large images or move backward or forward through Web pages or photos. Apple previously included multi-touch gestures in its notebook line, the Magic Mouse brings the technology to the desktop. The device is scheduled to be available at the end of October.

Finally, Apple upgraded the MacBook with a new ploycarbonate unibody design that features an LED-backlit display, a glass multi-touch trackpad and up to seven hours of battery life. The system, which has a 13-inch screen, includes a 2.26 GHz Intel Core 2 Duo processor, 2 GB of memory, a 250 GB hard drive, and Nvidia GeForce 9400M integrated graphics. The starting price of the MacBook remains $999.

The latest releases promise to heat up competition with the higher-end Windows PCs that manufacturers will be releasing soon with the latest version of Microsoft's operating system. Windows 7 is scheduled to be released Thursday.

InformationWeek has published an in-depth report on Dell's $3.9 billion buy of Perot Systems. Download the report here (registration required).