To try the thousands of add-ons available here, download Mozilla Firefox, a fast, free way to surf the Web!
CloseWelcome to Firefox Add-ons.
Choose from thousands of extra features and styles to make Firefox your own.
CloseReview for FireTray by revof11
Rated 4 out of 5 stars
This is a wonderful, simplistic plugin that does exactly what the description says. Fast, efficient, etc. etc. etc.
The only thing I would suggest is a right-click -> refresh all views option.
To create your own collections, you must have a Mozilla Add-ons account.