Part of the magic of Second Signal involves remote data collecting workstations. I'm using low power "thin client" machines with no moving parts, but they still need support once in a while for software upgrades and settings changes. Since these machines will be sitting behind almost any kind of consumer grade firewall and NAT router you can think of, I needed a way to remotely manage them that would -- most of the time -- not require me to spend time with clients reconfiguring their network settings.
Services like "GoToMyPC" could get really expensive when you starting thinking of dozens of (hopefully) hundreds of machines. I knew the open source community wouldn't let me down on this one, so with a bit of searching I came across a product suite built around VNC. The company "echogent" has packaged some open source client side software with a server offering they call "echoserver".

The echoserver acts as a sort of connection relay in the same way as the GoToMyPC offering does, and handles the firewall issues very well. In my testing, I installed the echoserver on my linux box at ServerBeach in about 10 minutes (most of which was spent setting up passwords) and then installed the client side (which is technically a server, since it serves your remote session) on both my workstation and on a virtual machine running within that workstation. It took me a few minutes to figure out, but I quickly was able to establish the remote control session.

The company, echogent, seems to have done an excellent job putting an echoserver together that runs on both Linux and Windows, and has controls such that you can manage your client side community with a fair degree of granularity in terms of who can see who. Passwords are not stored or sent in plain text, ports are configurable, and there are plenty of logging, debugging, and status querying features.

You can download the full package which includes the free stuff and the server product they sell with a trial key installed. Purchasing the server is very reasonable. It is $25 for personal use, and $200 for a commercial or enterprise license.

One last benefit that I didn't mention -- the author and I have exchanged a couple of emails and he seems like a good guy. I have a couple of questions still, but it looks to me like this is going to be a really great value for what I'm doing.