If you are a technophile at all, you will regularly have a need to diagram systems, networks, databases, or work-flows. For many years this functionally has been the domain of the very powerful and very expensive Visio program from Microsoft.
Fortunately someone has decided to liberate us from the licensing Goliath that is Microsoft by creating a Web 2.0 version of Visio called Gliffy . . .it can be found at http://www.gliffy.com
Gliffy allows users to create professional images online, collaborate with other desingated people or keep them private for your records alone.
Here is a very simple example that I created showing my home network:
The interface is exceptionally easy to use and there are a variety of shape groups you can choose from. This is great piece of software, I have not doubt they will soon be picked up by Google and added to their suite of products.
Once you have created your image online you can link to it or embed it in your website or blog:
Is is a pretty cool site.