Windows only: Portable utility Mute on Lock turns off your system speakers whenever you walk away and lock your workstation, but it also provides a quick shortcut key for toggling your speakers on or off.Once you've downloaded and launched the no-installation-required utility, your speakers will turn off immediately after pressing the Win+L shortcut key to lock your workstation, and then turn back on once you've unlocked your PC. If you head into the settings page, you can set up a custom shortcut key to mute or unmute the sound, or customize what the tray icon does. Definitely a handy utility for those of us that lock our workstations religiously, and it doesn't take up a lot of resources either.

Windows/Mac: Unfortunately the iPhone and iPod touch lack the ability older iPods had to run in Disk Mode. That's where iPhone Explorer steps in, allowing you manually manage files on your device, or just use it as a flash drive, without jailbreaking.iPhone browser is a lightweight application that has an easy drag-and-drop interface that lets you browse the contents on your iPhone. You can manually transfer your photos, music or movies from your device back to your computer, or just add files to the iPhone and fill up the unused space as extra storage. There's even an image preview for transferring photos. The best part about the whole thing, though, is that you don't need to jailbreak to use it. If you do have a jailbroken device, though, iPhone Explorer becomes even more useful—It can access the root of jailbroken phones and browse the files inside, with no need for complicated SSH setups.

Windows only: LookInMyPC generates a complete report of what's going on in a computer—from hardware to software, and everything in between. After playing around with it, this writer wouldn't start troubleshooting a PC without it. I'm not kidding.Whether you're a tech guru who knows your way around your computer better than the company that built it, or a novice just getting acquainted with your system, LookInMyPC is a free app you'll want to download and run at least once, even before you need its diagnostic help. It's like a big verbal X-Ray of your PC, detailing everything from the brand of network adapter you have to the number of user accounts on your system.

Windows: Ever download a movie from—oh, I don't know—some far-reaching nether-region of the internet, and when your download finishes realize the video is split into multiple parts? AVI Joiner quickly combines those split videos in just a few clicks.Using it could not be easier. Just run the app (AVI Joiner.exe), drag and drop the files you want to join into the Files to be joined pane, make sure they're in the correct order, and click the Run AVI Joiner button. The app will ask you where you want to save the joined video (name it and make sure to add the .avi extension to the end), then sit back as it fires up a command line and starts the joining process. I joined a couple of 700MB files into a 1.4GB video in roughly a minute.

Most of us remember Windows System Restore as a lame-duck feature from Windows XP; when it seemed we might benefit from using it, it never quite worked how we expected. That's no longer the case.Windows System Restore is an awesome system recovery tool, and it's included with Windows for free. It's the ideal solution for rolling back bad drivers, fixing when buggy software breaks your PC, or simply rolling you back to a previous point in time. If you've still got a bad taste in your mouth from the lackluster XP version of System Restore, it's time to take a look at it again if you've upgraded to Windows 7 or Vista.

Windows only: Spyware removal tool SUPERAntiSpyware has finally released an official portable version of their application, and, just like the installed version, it easily removes most infections on your PC in a single swipe.Once you've downloaded the application, the first thing you'll probably notice is the weird filename—each time you download it you'll be given a random filename, because most of the worst malware will prevent you from opening or installing any known malware removal tools. You'll be prompted for the language and a start screen, and then you can scan the infected PC immediately—the latest definition updates come with the download.

Windows only: The newest version of the popular Avast Antivirus is finally available for download. It's lighter, faster, and more feature-filled than ever, bringing a new behavior shield, heuristics engine, and code emulator to keep you protected at all times.Apart from its far easier-to-navigate interface, Avast has a few new features that make it hard to turn down. Its new code emulator can emulate a suspicious executable's code, isolated, for use in its new heuristics engine, designed to detect malware that would otherwise be undetectable with normal definitions—in other words, spotting malware by learning what the code does. If you use the pro version, you also get their new sandboxing feature for even further protection.

Windows only: The newest version of the popular Avast Antivirus is finally available for download. It's lighter, faster, and more feature-filled than ever, bringing a new behavior shield, heuristics engine, and code emulator to keep you protected at all times.Apart from its far easier-to-navigate interface, Avast has a few new features that make it hard to turn down. Its new code emulator can emulate a suspicious executable's code, isolated, for use in its new heuristics engine, designed to detect malware that would otherwise be undetectable with normal definitions—in other words, spotting malware by learning what the code does. If you use the pro version, you also get their new sandboxing feature for even further protection.

Windows: If you want a solid overview of what computers, networked printers, and other resources are available on your network, NetResView is a free, light weight, and portable application for doing so. NetResView is a stand-alone application capable of scanning your network and showing you all computers, printers, shared folders, and other network resources available on domains and workgroups your computer is connected to. From the NetResView interface you can see the resource name, type, what workgroup or domain it belongs to, its IP address, a local path if it's on the machine you're working on, the MAC address of the machine, and other information.

Firefox with Windows only: While traveling the internet, sometimes we don't realize how much memory our browser is hogging until it starts acting sluggish, hangs, or crashes altogether. Firefox extension Memory Fox optimizes your memory so you can surf without slowing down. Memory Fox keeps an eye on your browser's memory usage and notices when Firefox starts edging toward user-preset resource limits. When it does, the extension springs into action, automatically flushing your memory to recover space and keep your browser from slowing down.