The Acer M900 is geared more for the business user. The Windows Mobile 6.1 smartphone features a 3.8-inch WVGA touch screen and has integrated GPS, Wi-Fi, HSDPA, and a 5-megapixel camera.
With a slide-out full QWERTY keyboard, the M900 is built to handle your messaging needs. The smartphone also has a fingerprint scanner for security.
The Acer DX900 is the world's first smartphone to have dual SIM-card slots, allowing you to have two numbers. It's aimed at those who want different numbers for their work and personal life or for those who travel frequently.
Other features of the DX900 include a 2.8-inch VGA touch screen, Windows Mobile 6.1, and a 3.2-megapixel camera.
Unlike the M900, the Acer F900 doesn't have a slide-out QWERTY keyboard. Instead, there is a virtual keyboard and the smartphone has a widget-based home screen for easier access to applications.
The X960 is a little more consumer-centric, combining the typical Windows Mobile smartphone features with a more cell phone-like form factor.
On back of the X960, you'll find its 3.2-megapixel camera. Acer also touts the X960 as a convenient little navigation device with built-in GPS capabilities. In fact, all of Acer's smartphones will have GPS.