CursorSense is the only application that adjusts the cursor acceleration and sensitivity. By adjusting both values, you can move the cursor just like you move your hand. All mice and trackpads are supported. You can configure acceleration and sensitivity for each mouse / trackpad individually. No need to change the settings every time when replacing the mouse as you would have to in System Preferences.
There are many applications out there for changing the cursor movement, most of them free, but none of these are able to change the seinsitivity, or has per-device settings. CursorSense is the only application with both features.
All mouse and trackpad users. (Magic Mouse, Magic Trackpad and Mighty Mouse are all supported.)