@sun4u,
We are simply brainstorming here --- nothing personal!

Who wouldn't want freebies? I am a freeware fanatic as well, as I mentioned earlier. We heavily use Sun Solaris OS at the firm; in fact some of our home grown apps are made to run exclusively on Solaris Platform. While that is the sweet truth, there's a layer of horribly bitter truth as well ---- UPTIME in production environment is what a company primarily cares for, not necessarily refraining from investing on a handful of commercial tools.

One might argue, there is no better uptime on tools and OSes than the GNU licensed products -- I agree, but applications fail no matter how carefully they might have been written. I'm not a developer, and don't look into the 'open source' code to modify it as my preliminary incident response action. Even a group of a dozen developers cannot go through 70 thousand lines of codes to have system up and running in short time, trying to identify what caused the failure and how to fix it.

 There are priorities that take precedence, and priorities vary along with the nature of the firm. That's when you seek for support and expertise. It's beyond the reach of sysadmins when the burden goes beyond operating tools. If you are talking about a research firm or a lab environment of any given company, it makes complete sense to fully rely on the open source; otherwise what am I to do with the source being open?
 
There is a reason why companies set aside a substantial portion of their budget to spend on state-of-the art applications.

Now, getting back to your suggestions on the tools. Thank You for listing them; but here's some additional info:

Wireshark and TCPDump are Packet analysis tools
NMap is merely a port scanner
OPENLDAP is the free version of LDAP -- nowhere close to SSO (Single Sign On allows a user to consolidate all credentials into one, such that one time sign on opens the 'Golden Door'. It's an absolute must for thousands of employees who aren't tech savvy)
RSA Authentication: RSA is no longer limited to being an algorithm; it's a copyright product owned by EMC; RSA Authentication = Two Factor Authentication.

Once again, it's simply a brainstorm.

I use SNORT everyday as my IDS --- I love it, I worship it, I back it -- BUT the reason behind using it besides being free is, IT IS COMPLETELY OPTIONAL; the firm runs equally well even if my IDS fails.

However, not letting your zeal go down & sticking to the topic: Hope your blog/forum site starts and stays well, and would bring interesting topics such as DTRACE    :)

cheers!

~@~