As for the controller's design, Sony has made a few tweaks since the old PS2 version. The L2 and R2 trigger buttons are slightly bigger, and the increased depth in stroke offers players more subtle game control. Sony has also increased the tilting angle of the analogue joysticks to give you more precise control and a wider range of motion. Those analogue sticks are more sensitive as well. The PS2's Dual Shock 2 controller had 8-bit sensitivity, while the PS3's controller has 10-bit motion detection. The Sixaxis and DualShock 3 controllers also have a centred Home button, which functions much like its counterpart on the Xbox 360 controller. You use it to return to the console's main menu screen, as well as to sync the controller to the console and start it up or shut it down wirelessly. In game, the Home button will now bring up the cross-media-bar (XMB).
The other major upgrade on the DualShock 3 (and Sixaxis) from its predecessors is its motion sensitivity. As the name indicates, the controller is capable of sensing motion in six directions: up, down, left, right, forwards and backwards. Game developers have incorporated this technology in many of the new games in one form or another. For example, in Call of Duty 3, you can arm explosives with a twist of the controller. The basketball game NBA 2K8 also makes interesting use of the tilt feature, allowing you shoot free throws by motioning a shot with your controller.
After almost two years of titles, some implementations of the tilt sensitivity are better than others. Some games' use of it are optional and can be switched off, as we can certainly see some people not wanting to bother with it at all. Clearly, Sony wanted to steal some of Nintendo's interactive thunder, and there's no denying that the Wii's motion-sensitive controllers are more central to that console's DNA. The Wii controllers are also more sophisticated, including the capability to measure actual motion (spatial movement) and acceleration, rather than just tilting.
But unlike the Wii, the PS3 doesn't require a motion-sensor bar in front of the TV. (The current Xbox 360 controllers offer no motion sensitivity at all.) It's safe to say we'll see more innovative uses of the tilting sensitivity feature in future games as it definitely adds an extra level of control when flying the eponymous attack vehicle in Warhawk or controlling the trajectory of an arrow in Heavenly Sword. On the other hand, the highly touted Lair is widely considered unplayable, thanks to a poorly implemented Sixaxis control scheme.
If you own a Sony PSP, you'll immediately notice the similarities between the PS3's interface and the PSP's cross media bar-style graphical-user interface (GUI). You navigate horizontally through top-level selection categories such as users, system settings and media options -- photos, music, videos, games, network and friends. When you select a top-level category, a vertical list of sub-options appears.