Right click on items on the Ticker or any Touchstone Alert and you can now Digg/Reddit/Del.icio.us/Etc it right there!
Developers can even add their own 'ActionExtensions' by writing a little bit of XML.
If you are developer: Read more about it here
Also, since this type of extensibility is a first in the Feed Reading space (as far as we know) we would be interested in collaborating with other feed readers out there to add universal support and working with app developers to build their own plugins for the Subscription Helper. Drop me a line.
Don't have an invite yet? Maybe you should pay more attention.
Unfortunately, due to the complexities of the Gmail authentication system, attempting to subscribe to http://gmail.google.com gets you nowhere. All is not lost however! Subscribe to https://mail.google.com/mail/feed/atom, enter your username and password, and Touchstone will check gmail for you. Nifty.