• The popular Android market has more than 100,000 apps.David Roth/Stockbyte/Getty Images
  
  The majority of open source mobile devices today run the Android operating system from Google. Android participates in the Open Handset Alliance, which is a group of software and hardware developers and telecoms committed to open standards for mobile devices. There are now more than 100,000 apps for Android phones, and popular models include the Motorola Droid X, the HTC Evo 4G and the HTC Droid Incredible.
  
  

Motorola Droid X

• The Motorola Droid X has been available since July 2010 from Verizon and costs $200 with a two-year contract. It has a large 4.3-inch screen, captures 720p high-definition video and has an 8-megapixel camera. It has expandable storage -- 8 gigabytes is built-in, but you can expand it up to 40 gigabytes.
  
  

HTC Evo 4G

• You can get the HTC Evo 4G on Sprint for $200 with a two-year contract. It offers 4G speed which is great for high-bandwidth users. You can use it as a roaming hotspot for up to eight devices. It also has a 4.3-inch screen and 720p video.
  
  

HTC Droid Incredible

• You can get the HTC Droid Incredible on Verizon for $200 for a two-year contract. It has an 8-megapixel camera, 3.7 inch screen, and is one of the fastest Android phones. It also offers a streamlined design.