Microsofts Semantic Web Clipboard
Microsoft has created an (demo) application - the "Live Clipboard" - that extends the clipboard user model to the web. It allows to copy structured data from the web or local applications and paste that data to local applications and other web sites while retaining the structure. For example you can copy the information about an event that is represented in the event microformat and paste it to your local Outlook application or your Google calender. In the case of copying to the local outlook the Live Clipboard tool takes care of translating the event microformat to a format outlook can understand; in the case of the Google calendar website, it is expected that the website can understand the XML format. You can learn more about this on Ray Ozzie's Blog there you also find a screencast explaining Live Clipboard in detail. .
The release of such an application could be a very big step towards the realization of the Semantic Web !