[eluser]Phil Sturgeon[/eluser]
Ok, so this is fairly similar to the Widgets base-code, your implementation is just a little different.
PyroCMS works around 3 tables.
widgets - details about the actual widgets available. RSS feed, Twitter stream, etc.
widget_instances - A specific instance of a widget contains specific data (rss URL or twitter username)
widget_area - Where will these widgets be going in the site?
You will need it to be a little different. You just assign a widget instance to a user instead of a widget area.
I suppose the "widget plugin" you're talking about wiredesignz's? It is fairly good, but you need much more implementation code and PyroCMS might steer you more in the right direction that you would with just his basic library.