I also would very much like tasks to have a status that could be marked as active/on hold/dropped. Such a status is probably most meaningful in "Single Action" projects, although one might have a need to mark any task in any project as "dropped". (For more discussion see
http://forums.omnigroup.com/showthread.php?t=6670)
I am currently marking "on hold" tasks with a "Pause" context, and mark this context as "on hold". (Contexts in OF can be marked as "on hold".) I can then easily filter these tasks out from my view. This definitely works, but it means losing the orginal context of the task. Recalling the original context when I "un-pause" the task is generally not an issue, but can sometimes take a little more effort than desired.
Thanks!