From stumblers to help you detect nearby networks, sniffers to see the data, and replacement firmware projects to supercharge your network, here are 10 different applications you might find useful when installing, securing, or using private or public networks.

1. NetStumbler: To Find Nearby Networks

This is a simple stumbler that shows you the details of nearby wireless networks or access points (APs). You'll see each AP's MAC address, SSID, channel, encryption status, signal, noise, signal-to-noise ratio, and more.
NetStumbler is handy when installing a new network or AP. You can check for possible interference from neighboring or existing APs. You can also use it to verify coverage and proper positioning of APs by referencing the signal strengths.
You might even take a stumble once in awhile to check for rouge nodes or other problems.

2. Network Magic: For an Easier Networking Experience

If you or your users are new to networking, you might find Network Magic useful, especially for use with Windows XP or earlier. Network Magic is a program that can replace most of the networking interfaces built into Windows with ones that are more understanding and user-friendly.
Plus it provides additional functionality, such as being able to edit settings on the network's router.

3. DD-WRT: To Super Charge Your Cheap Wireless Router

This isn't a program to install onto your computer; it is replacement firmware you can upload onto supported wireless routers.
DD-WRT gives you improved and new features, plus advanced ones that are usually available only in enterprise-class equipment.
Example include multiple SSIDs so you can offer varying encryption methods to the same or segregated networks and a built-in VPN client and server so you can securely connect offices together or offer connections to remote users.

4. Wireshark (Previously Ethereal): To See the Raw Traffic

Wireshark is a network protocol analyzer that captures, inspects, and displays the raw traffic of many networking protocols.
It runs on just about any platform: Windows, Linux, Mac OS X, and many others. It has an easy-to-use GUI and a TTY-mode.
You can use this tool to help understand what's really happening when you're trying to troubleshoot problems on the network. You can browse, search, and filter through the traffic.
If you don't understand the protocols that well, it gives you a chance to familiarize yourself.
Wireshark can also save packet traces for later inspection; open standard formats from other analyzers; and can be exported to XML, PostScript, CSV, or plain text.
In addition, capturing Ethernet and wireless traffic, Wireshark can read from USB, Bluetooth, Token Ring, ATM, and more.
If you use any encryption, such as WEP, WPA, WPA2, Ipsec, or SSL/TLS, you can configure Wireshark with the keys so it can decrypt and display the actual data if needed.

5. TeamViewer: For Remote Desktopping

Windows, Mac OS X, and Linux all have remote desktop solutions[md]however, they aren't all compatible. Using one protocol and application makes it much simpler when working with multiple platforms. The operating-system developers don't make it really easy to use their solutions, either.
One solution is to use a third-party application such as TeamViewer.
In addition to being able to fully view and control remote computers, TeamViewer lets you transfer files between PCs, all behind firewalls.
You don't even have to install the application on the remote computers. You can download and run it directly from the file or take it around on a USB flash drive, or even use the Web-based interface from just a browser.
Everything is also secured with AES (256-bit) encryption.
As the name suggests, this remote desktop software is good for groups or teams. You can create a buddy list to keep track of others' availability.
You can also use it for presentations and invite people right from the application.

6. NetSetMan: To Manage Your Network Settings

NetSetMan is quite helpful if you use multiple networks. It lets you save up to six different sets of profiles, loaded with many network settings.
Then when you connect to different networks, you can easily switch between your profiles and NetSetMan will automatically apply your desired settings.
If your work uses static IP addresses, for example, you can set up a static IP for your work profile along with any DNS, Workgroup, or other settings.
Then you can have another profile for when you connect to your home network, set to get your IP automatically, a different PC name, workgroup, and other settings.

7. LogMeIn Hamachi: To Create a Secure VPN

If you have multiple offices or locations, you'll probably want to connect their networks together. That way everyone can access shares and network drives, just as if each location were physically connected by a cable.
You can securely connect offices together like this by creating a virtual private network (VPN). One way to do this is to use the LogMeIn Hamachi application.
After you install LogMeIn Hamachi onto a computer, you create a network and get an address.
Then on other computers at that or other locations, you can join the VPN network, and they all would be connected together.

8. Gbridge: To Securely Share Among Friends

Although this one is similar to the previous solution, it takes a different approach.
Instead of just connecting the computers together, Gbridge offers its own proprietary interface. It is designed more for sharing with friends instead of among your own computers.
Once you install and sign up for the service, you can give out your address to others or invite them, so they can join your VPN. Then everyone can choose what they want to share.

9. Hotspot Shield: To Secure Your Wi-Fi in Public

VPNs have a few different uses. One is to secure your connections on public networks such as Wi-Fi hotspots or wired Internet ports.
While connected to a VPN, all your Internet traffic goes through the secure tunnel to the endpoint (your office).
Therefore, if you use a VPN while on an unprotected network, all your Internet traffic is encrypted by the VPN tunnel.
Hotspot Shield protects against any nearby eavesdroppers or hackers.

10. Undelete: So Network Shares Can Use the Recycle Bin

This isn't necessarily a networking program or tool. However, Undelete is a third-party replacement recycle bin supports shared folders.
If you delete a file from a shared folder of a different computer on the network in Windows, it's usually gone forever. However, when using Undelete, shared files go into the recycle bin where you can keep them for awhile in case you need to recover them later.