Unless you are using IE 32-bit, don’t expect the Clearspring widgets to work. Clearspring is one of the leaders in building widgets for social networks and Vista. The reason their widgets do not work is because Flash is not yet supported on 64-bit platforms. By default, the Vista Sidebar on a 64-bit system displays widgets by using IE 64-bit.
An example of a Clearspring widget in the 2008 Beijing Summer Olympics widget from NBCOlympics.com.