You don’t have to wait for Longhorn to use sidebar. Try Desktop Sidebar!
Aim of Desktop Sidebar is provide the user with instance access to some of their most important daily information. Desktop Sidebar is tightly integrated with Outlook XP, Windows Messenger and Windows Media Player. Following panels are available: Clock Panel, Calendar Panel, Task Panel, Inbox Panel, Notes Panel, Messenger Panel, Newsroom Panel (RSS/RDF Newsfeed viewer), Performance Panel, Disk Monitor Panel, Media Player Panel, Toolbar Panel, Weather Panel and Search Bar Panel.
Tools and Utilities
1.05 Build 88 Beta
Product page: here