Allocatus follows a different more intuitive approach. If you enable the "WriteBack" feature, all Allocatus appointments in the calendar up to yesterday will update the actual work in Project Web Access (PWA) timesheet. All appointments in the calendar beginning today or later update the remaining work in the PWA timesheet.
Please see the screencasts available at
http://community.allocatus.com/files/folders/allocatus/entry150.aspx (for Outlook)
http://community.allocatus.com/files/folders/allocatus/entry151.aspx (for Lotus Notes)
Note, we are using the standard Notes and Outlook forms. That means you can update your timesheet also from the Outlook/Domino Web Access and any mobile device, like your Smartphone, Pocket PC, Backberry, etc.