First on our sharing list: the ability to embed an automatically updating list of your NetNewsWire / NewsGator subscriptions into your website or blog. To enable this, simply sign into your NewsGator account (if you're using NetNewsWire 2.1.x or 3.x I believe you automatically get at least a 1-year NewsGator subscription) and go to Settings > Edit Locations. Assuming you have syncing with NewsGator enabled, you should see at least one location related to your NetNewsWire feeds which should have a 'Blogroll' option listed. Clicking on that will give you all the options you need to embed a small snippet of code in your site to create a list of the subscriptions you want to share publicly.
There is another way to share your NetNewsWire subscriptions in a handy-dandy file format, easy for friends, family and visitors to download and import into just about any newsreader they use, including NetNewsWire, Google Reader and even Vienna (this is technically referred to as an OPML file, with the extension .OPML). NetNewsWire offers a File > Export Subscriptions command, but there are a few options involved and this isn't very automation-friendly. If you want to make your subscriptions available to, for example, website visitors or simply back them up on a regular basis, I put together two very basic, two-step Automator apps (packaged as zip files) that can work fine on their own or easily be incorporated into larger workflows.
Export NetNewsWire feeds
All these actions do is select a specific destination on your Mac and export your entire list of NetNewsWire subscriptions in group format (maintaining any folders you have created to organize your feeds into) as 'Subscriptions.opml'. The first app - Export NNW to Desktop - simply exports an OPML file to your Desktop, while the second - Export NNW to iDisk - will export this same OPML file to your iDisk's Public folder. The second one is a bit more useful because you can link your iDisk's Public folder so site visitors have easy access to it; the HTML link for your public iDisk folder is formatted like this:
With this second app, all you have to do is run it (by double-clicking, calling it via a utility like Quicksilver or assigning a keyboard shortcut to it) and your Subscriptions.opml file will be created or updated automatically, and your iDisk should kick into gear and upload the new file as well (of course, this assumes that you have your iDisk mounted automatically like I do. If you don't, you might have to mount it manually, as I can't find an Automator action for that. Suggestions are welcome).
This is a simple tool in and of itself, but it can get a lot more powerful if you add this app into an Automator workflow with more actions. For example: website operators could open this NNW export app in Automator (simply drag it onto the Automator window or icon in the dock to open it for editing) and add FTP actions to it so the app not only exports NNW subscriptions, but it also automatically uploads the resulting OPML file to an FTP location, updating what could be a file that is always linked and shared somewhere on their website. Other users could simply attach Automator actions that email the resulting OPML file off to a friend or co-worker, or send a copy of the file to a backup location for safe keeping.
The sky is the limit with Automator, and even though some of the actions take a little tinkering to understand and work properly, I'm falling more and more in love every time I open it. These actions are by no means special and they weren't very hard to create, but I hope they can help at least a few readers get a better grasp on how to work with making automate-able Mac OS X apps create files like this. As always, feel free to ask questions and I'll do my best to answer.