While all things beginning with “i”—i.e., the iPhone and iPad—will surely be hot this holiday season, Apple is facing a bit more competition this year.

For one thing, Microsoft has waded back into the smartphone fray with new Windows-based handsets for the Christmas shopping season. That adds to the anti-Apple competition, which has been led by BlackBerry and newer phones running Google’s Android operating system.

On the tablet front, Dell Computer, BlackBerry maker Research in Motion and others are bringing out iPad rivals. In the e-reader space, prices keep coming down, tempting shoppers more inclined toward books than video games.

Microsoft’s new smartphones run an updated version of Windows mobile software. The Windows Phone 7 handsets are compatible with Microsoft Office, play music through Microsoft’s Zune and offer Xbox games. The company says the phones provide a simpler interface for users through a smaller number of larger “tile” icons. The handsets from manufacturers, including Samsung, HTC and LG, come in a variety of models, with touch screens or slide-out keyboards, little kickstands to set the phone upright, and—in one case—a slide-out speaker. Carriers include AT&T, Verizon, Sprint and T-Mobile.

As a latecomer, Microsoft faces daunting competition from the iPhone and from Android handsets, which have been gaining market share in leaps and bounds with phones such as Motorola’s Droid X and the HTC Incredible. In addition, BlackBerry remains a mainstay of business. It still boasts the largest—albeit shrinking—share of the U.S. smartphone market, with 37.6% at the end of August, according to Comscore, followed by 24.2% for Apple, 19.6% for Android and 10.8% for Microsoft’s older devices.

The new Windows phones also have to overcome the app-gap. Google now offers some 80,000 applications for Android phones, while the iPhone has about a quarter million apps—and counting.

In addition, Microsoft faces a big post-holiday challenge. For shoppers who can wait, the largest U.S. mobile carrier, Verizon, will begin offering the iPhone for its system. Until now, AT&T had been the sole iPhone carrier, leaving many potential customers sidelined.

While Verizon won’t offer the iPhone until next year, it did get a headstart on holiday shopping with that other hot Apple product, the iPad. For now, at least, there is a catch. Customers who buy the Wi-Fi-enabled iPad from Verizon will also need to buy its MiFi personal hot spot device if they want to connect to the carrier’s 3G network, which runs on a different mobile standard. AT&T customers can simply connect to the carrier’s network from the iPad.

In the tablet arena, Apple also faces new competitors.

Korean electronics company Samsung is expected to launch an iPad competitor in time for holiday shopping. The Android-based, 7-inch Galaxy Tab will be offered by the major carriers in the U.S. Pricing was not immediately available.

Computer maker Dell has a 5-inch tablet called the Streak that makes voice calls, which the iPad doesn’t, and which is roughly half the size of the iPad. Dell plans to launch a 7-inch tablet this fall and a 10-inch tablet within the next year.

Research in Motion’s new tablet will also miss the holidays. The BlackBerry PlayBook, due out early in 2011, will feature a 7-inch screen, but initial versions will be able to connect to the Internet via WiFi only. Later versions will include 3G and 4G.

If the person on your gift list is more interested in words than pictures, your tablet of choice might be an e-book reader, which came down significantly in price over the last year.

Of course, there are many other possible gadgets out there, ranging from the useful, such as “smart pens” for college students who can record lectures and notes, to the playful, such as GPS-equipped ski goggles for skiers going off the beaten path. Happy shopping.

The hot toys:

  • iPhone, 3GS from $99, 4GS $299, with service contract. www.att.com
  • iPad with Wi-Fi, $499-$699; Wi-Fi and 3G, $629-$829. www.apple.com

The newcomers:

  • Microsoft Windows Phone 7-HTC Surround, Samsung Focus, LG Quantum, all $200 with service contract. See www.att.com or your carrier.
  • Dell Streak, 5-inch screen, $300 with wireless service contract. www.dell.com

For readers:

  • Amazon Kindle, 6-inch screen, Wi-Fi, $139; with 3G, $189; Kindle DX, 9.7-inch, $379. www.amazon.com
  • Barnes and Noble Nook, Wi-Fi only, $149; with 3G, $199.
  • Borders Kobo, with Wi-Fi, $139. www.borders.com

For studiers

  • Livescribe smartpens, $130-$200. www.livescribe.com

For skiers:

  • Zeal Optics Transcend GPS Goggles: $400-$500. www.zealoptics.com