It is often worth grabbing a few utilities in order to keep your Mac in the best possible shape, whether you're looking to improve your wireless connection or just to boost performance. What follows is a selection of utilities which may boost your Mac life.

AppCleaner (Free)
You may not be aware of it but every application you install on your Mac distributes a host of support files across your System, nestling these inside various preference and other folders.

Unfortunately, applications don't delete their support files when you choose to delete the application, bloating your drive with useless clutter.

To get rid of an application and all its trace files you need AppCleaner, an icon-based solution which finds and deletes all an applications associated files when you delete the software, reclaiming valuable space.

LittleSnitch (€29.95)
Any active application can send out information to external places from your Mac when they are online. How can you tell which applications are doing this, and how can you control what information they send? Simple -- install LittleSnitch.

This utility monitors your system and lets you know when applications are attempting to make an outgoing connection. You can then choose to allow benign requests, while forbidding unwanted communication attempts.

Little Snitch runs inconspicuously in the background and can also detect network-related activity that indicates viruses, trojans and other malware.

Onyx (Free)
There's other solutions for this (Cocktail, for example), but I use Titanium's Onyx, an essential utility designed to keep your Mac in fantastic shape.

[This story is from Computerworld's Apple Holic blog. Follow on Twitter or subscribe via RSS to make sure you don't miss a beat.]

The French developer describes Onyx as,

"A multifunction utility for Mac OS X which allows you to verify the Startup Disk and the structure of its System files, to run misc tasks of system maintenance, to configure some hidden parameters of the Finder, Dock, QuickTime, Safari, iTunes, Login window, Spotlight and many Apple's applications, to delete caches, to remove a certain number of files and folders that may become cumbersome and more."

I've been using it in its various iterations (it gets updated swiftly subsequent to the release of any new OS X upgrade) for many years. I make particular use of it to run Maintenance and Cleaning tasks manually, as this invariably speeds up my system and reclaims drive space.

Dropbox (Free basic service)
Dropbox is free and incredibly easy-to-use. Once installed it enables you to sync what's on your Mac with all your other Macs. There's even an iPhone/iPad app so you can access your most important research and other documents while you're on the move, and you can create shared folders which allow groups of people to share and collaborate on files.

This is iDisk without the high annual fee. It is also far more powerful and configurable than iDisk. Every Mac user should have a Dropbox account.

iStumbler (Free)
This fantastic free open source tool helps you find wireless networks and devices using an AirPort or Bluetooth equipped Mac.

You can use iStumbler to find free or unsecured WiFi networks to jump onto, but it can also help you boost your own home wireless network.

Here's the situation: WiFi networks are spreading fast. In built-up areas (I'm London-based, for example) you find that people in flats near your own are coming online with WiFi networks of their own. Sometimes you get network interference, particularly when two or more networks are on the same channel.

Using iStumbler you can take a look at all the networks in your area. You can check which channel each network is on, assess which networks are most powerful (yours should be the most powerful) and then use this information to determine which channel to put your network on.

For example:

You may find that your network is on channel 11 with one or more powerful neighboring networks also on the same channel. The effect is to slow down your traffic. Looking at iStumbler you may find that channel 4 is very quiet, with few networks on channels to either side of 4. Launch AirPort Utility abd then choose the new channel from the Channel pop-up menu. You should see immediate improvement in your wireless network performance.

And one more thing (number six)

Disk Drill (Free beta available)
Sometimes it happens -- someone may accidentally delete important files from their system, or from an external device such as a memory card or hard drive. What can you do?

There's no need to panic as there's numerous data recovery solutions out there. New application Disk Drill seems promising, as it offers a relatively straightforward UI and has proven pretty effective in my brief tests.

Disk Drill will have a good attempt at recovering deleted files on Mac from your disk, camera or memory card. It also offers a feature called Recovery Vault, which helps you protect your files against accidental deletion.

Be warned: the software is available free at the moment, but it is a beta, so it is at your own risk. If you have the cash, just $99 will get you ProSoft's tried-and-tested Data Rescue 3 for Mac, which I have used to rescue critical data.

So there you have it: five recommended utilities and a sixth to kick around a little. I'm curious what other utilities readers might think essential.