Heh... when I saw that subject in the recent posts list, I thought it was a Time Out query, as that is one of the most popular requests... and something planned for Time Out 2, coming in a few months.

But Simon... that's a new one. As it happens, I do have plans to add that option in a future version of Simon (after the upcoming 2.6). So the answer is: not yet, but in the future, yes.

In the meantime, a workaround is to use a tool like Dockless to hide Simon from the Dock.