Here are 5 Mac utilities that alter the mouse acceleration curve, speeds, and/or add features to mice in OS X:
USB Overdrive
$20 (Shareware; Free unlimited, fully functional trial)
USB Overdrive is a popular program
that works with just about any USB or
Bluetooth input device. It allows
users to customize mouse acceleration,
scrolling, clicking, and more. You can
even configure per-application
settings. A new version that supports
Multi-Touch in Apple’s Magic Mouse is
in development and expected soon.
Version 3.0.1 compatible with 10.4, 10.5, or 10.6
SteerMouse
$20 (Shareware; Free 30 day trial)
Aside from mouse acceleration,
SteerMouse offers a ton of other
advanced features. Configure up to 16
buttons, modify scroll wheels/balls,
and set the cursor to automatically
move to a specific location on the
screen when a window is activated.
Support for the Apple Magic Mouse is
pending.
Version 4.0.1 compatible with 10.4, 10.5, or 10.6
MouseZoom
Free
While MouseZoom does not alter the
acceleration curve itself, it does let
users bump tracking speeds beyond
those available in System Preferences.
An ideal solution? No, but it’s a free
alternative that helps ease the pain.
Version 2.2 compatible with 10.1, 10.2, 10.4, 10.4, or 10.5
Mouse Acceleration
Free
This Preference Pane is based on
Richard Bentley’s MouseFix – a
non-user-friendly command line
utility. This version, however, makes
it easy to increase mouse precision
and speed up mouse movement with
visual aids.
Version 1.0 compatible with 10.4 or 10.5
BetterTouchTool
Free
This is a brand new piece of software
that just came to be within the past
couple weeks. It’s in beta and still
buggy, but it packs some nice features
and is in active development. I can’t
say for sure whether it customizes OS
X’s acceleration curve or just
supercharges the maximum tracking
speed. The real reason to give it a
shot, though, is if you have a Magic
Mouse or MacBook that supports
Multi-Touch gestures. BetterTouchTool
lets users assign specific actions to
advanced finger gestures and can
simulate a middle-click. It can even
bring the Mighty Mouse’s Exposé
functionality to the Magic Mouse.
Compatible with 10.6
ControllerMate
$15
ControllerMate is a controller
programming tool that allows you to
customize the behavior of your HID
devices — keyboards, keypads, mice,
trackballs, joysticks, gamepads,
throttles, among others.
ControllerMate’s philosophy is to be
as flexible as possible, to provide a
set of basic programming tools, and to
allow the user to combine those tools
in an endless variety of ways.
SOURCE: This was posted on Nov 24th, 2009 at MacYourself.com. Some utilities are probably updated now. I’ve used USB Overdrive with certain success.
In OS X 10.9 and later:
pmset displaysleepnow
By itself, this command only causes the display to sleep, resulting in a black screen. By configuring your computer to require a password immediately after sleep, this one-liner works as a "lock computer" command. The preference is available at System Preferences > Security & Privacy > General.
Source: How to lock screen on MacBook Air?
Best Answer
In Logitech Options, you can assign a keyboard sequence to a button. For this example, I assigned the top button on the side (the one highlighted in green) the shortcut to lock the screen CommandControlQ.
Now, when I press the button, it's as if I've pressed the keyboard shortcut.