On the offchance that this is of interest/value to someone else here is 'a' solution (not necessarily 'the' solution)
the script generates up to four popups to enable you to track up to 4 (
) concurrent tasks or activites (this seemed like a reasonable number, plus it was the maximum number that would fit comfortably on my netbook screen)
time/activity tracking toolfirst popup is generated on startup, and additional 'tasks' can be added via a hotkey (WIN+1 or WIN+NUMPAD1, and up to a maximum of 4 at any one time) .
each popup displays the task number and the start time in the title bar, and both the duration of that task (in minutes) and the current time in the status bar
Pressing continue hides the window for 5 minutes (after which it reappears)
Pressing Done cancels the window (task) and writes a log entry in the format "DD/MM/YY HH:MM (Duration) - content of the edit box" (the log file is in the same folder as the script/exe). If the edit box is empty no log entry is written.
There is a 'lunch' hot key as well (WIN+0 or WIN+NUMPAD0) - invoke the hotkey and all tasks are hidden for 45 minutes. After 45 minutes all active tasks are shown, AND the durations adjusted to allow for the 'lunch break'.
Worth noting that by definition this is nagware - that is to say that there will ALWAYS be at least one task window active, ie close all the active tasks and a fresh (blank) task will be presented. Note that you don't actually have to enter anything for the task to run, but if you don't no log entry will be raised.
The title for this is fairly nominal 'cos I couldn't think of anything better that wasn't already in use - it's an acronym for Damned if You Do...
edit: adjusted screenshot size...