I know top X lists are almost passe at this point, but that's not going to stop me from giving a shout-out to some of the applications that daily make my life easier:
MarcoPolo is a neat little application that is capable of executing actions based on a set of rules. That is, if something on the system changes (such as an IP address, power status, USB or even the light level), it can execute a series of commands (such as mounting network drives, setting the screensaver, changing the default printer, etc). It can even run arbitrary shell scripts!
Why this is useful to me: At dealnews, we (the dev team) all use MacBook Pros for our development work and constantly alternate between home and office. Whenever I arrive at work in the morning, the minute I plug my MacBook into the network, MarcoPolo senses that the IP address has changed from my home and changes the default printer, mounts some network shares, adjusts the screensaver settings, and runs a few other custom shell scripts I have to set up my environment. All without having to do a single thing. When I get home, it executes still more commands to change to a remote development environment. Completely effortless.
XMeeting is a SIP softphone (and videoconferencing application, but I've never used the video features) that allows you to connect to a SIP server and place calls using your laptop.
Why this is useful to me: At dealnews, we run Asterisk as our phone system (see my earlier posts on Asterisk). One of the many nice features of Asterisk is its standards compatibility - that is, you can use anything that can talk SIP with Asterisk. Since CounterPath has apparently decided that Leopard compatibility for their free softphone (X-Lite) is not a priority, XMeeting comes to the rescue. As a bonus, it actually acts like a Mac application and doesn't do the stupid things that X-Lite did (like messing with the system volume).
Quicksilver is the single application I cannot live without. On a Mac without it I am almost lost. More than just a launcher, it is a tool to help you work more efficiently. You can press Ctrl+Space and type what you want and Quicksilver will launch what you need. That's a horrible description for how cool this app is.
*Why this is useful to me: *Without Quicksilver, I am lost. It makes it literally so fast to move around your Mac without taking you hands off the keyboard. A quick hit of Ctrl+Space gives you the ability to launch programs, open files, navigate contacts and send emails, and make quick notes among many othe things that this program can do. It is essential to my everyday life as a Mac user.
DejaMenu is a neat little program that will display the current application's main menu as a popup menu where the mouse is whenever a key combination is pressed.
*Why this is useful to me: *I use my MacBook Pro with a second monitor when I'm at the office. One of the things that has infuriated me for awhile as a Mac user with multiple monitors is the inability to have the top menu bar either on each monitor respresenting the application on that monitor, or the ability to have it move with whatever monitor the mouse is on. It's irritating to have to go back to the main monitor when the application is running on a different one. DejaMenu allows you to pop the application menu wherever your mouse is, which makes things a little easier. Additionally, I mapped the key combination to a button on my Logitech MX-1000 to make things even easier.