PBwiki has several plug-ins available, on this page are the Productivity plug-ins.

 

Any Google Gadget, such as this weather module.

See other choices here.

Plugin error: googlegadget (Plugin not found ../common/plugins/googlegadget.inc)   

Or an asynchronous message board.

Plugin error: googlegadget (Plugin not found ../common/plugins/googlegadget.inc)

Or any RSS feed that you want to capture

Plugin error: googlegadget (Plugin not found ../common/plugins/googlegadget.inc)

A calendar from 30 Boxes, perhaps?

A stock chart with daily, 3 mon., 6 mon., or 1 yr. time horizons?