An excellent program for monitoring users and applications is psacct. This program will work in the background of your system recording what all users are doing on your system as well as the resources that are being consumed. I originally started using this program when a client asked for a way to monitor his developers and what they were doing on the servers that they were working on.

The GNOME Activity Journal is a tool for easily browsing and finding files, contacts and other resources on your computer. Using Zeitgeist, it keeps a chronological journal of your activity and supports tagging and bookmarking (using the new Tracker 0.7) and establishing relationships between resources.

A look at some more security on-the-cheap, using mkfifo.

Your GNU/Linux computer is an amazing machine. It can display images. It can run programs. It can perform dozens of functions all at the same time. How can you keep track of all this activity? By monitoring the processes that your computer runs, and one of the best ways to monitor and control processes is by using the command line.

ZABBIX is an enterprise-class distributed monitoring solution designed to monitor and track performance and availability of network servers, devices, and other IT resources. It supports distributed and Web-based monitoring, auto-discovery, real-time monitoring, SLA assurance, trending, and more.

Enhance regulatory compliance and troubleshooting through detailed auditing, logging and real-time monitoring of UNIX/Linux user activity.

Social Media Monitoring (sometimes called social media listening or conversation monitoring) is widely recognized as one of the first social media best practices. It is the first step in getting to know and understand the behavior and needs of an online audience. Most companies that are engaged in this activity have an internal team or outsource the effort to their agency.

Wireshark is a very versatile utility to monitor all the neighborhood network activity, including disassembling packets and viewing data transmitted from anyone who is connected on your LAN (or Wireless LAN). I'm using Wireshark to monitor the activity of the network, and I explained the packets transmitted between the peers.

For added protection, you can run a power-monitoring utility that will read status information from the UPS and perform a clean shutdown of the connected machine (or machines), preserving data and stopping processes in the proper state.