Let me just chime in 'ere:  yes!  More placement options.

So far, you have RowSmartPlacement, UnderMousePlacement and RandomPlacement (the latter not being in fluxbox);  it'd be nice to also see ColSmartPlacement (as suggested), *as well as* CascadePlacement and NotUnderMousePlacement, the latter only available as a patch on sourceforge.

Also, it'd be nice to have a way to specify your preferred order in which to try the different placement strategies; something like

<placement>
  <policy>Transient<policy>
  <policy>NotUnderMouse</policy>
  <policy>UnderMouse</policy>
  <policy>RowSmart<policy>
</placement>

And the semantics would be similar to that of place_client in place.c

(It's implied that NotUnderMouse would be smart and try to do a RowSmart placement while still dodging the mouse, if possible; see the patch to fluxbox).

*** Bug 2752 has been marked as a duplicate of this bug. ***

(In reply to comment #2)
> *** Bug 2752 has been marked as a duplicate of this bug. ***
For the record: bug 2752 has a patch attached to it which implements this.

im a little unsure what the point of notundermouse is.

if you're using mouse focus, then the mouse is in the focused window, probably, and placement will avoid that window more than anything else.  (previously the enter event would end up giving the window focus, now it wont unless underMouse is true)

if you're not using mouse focus, then the mouse could be anywhere and i don't see the point of trying to avoid it.

It would be great if we could configure whether the smart placement algorithm first fills columns or whether it first fills rows.
I guess that's what Jonas meant when he mentioned "RowSmartPlacement".

Currently, it seems fill-columns-first is the hardcoded behaviour (3.4.3).

One point to think about is whether openbox should fill rows spanning all screens, or whether it should first fill one screen completely before moving to the others (currently, it first fills one screen). Maybe this should be configurable, too.

It doesn't use columns or rows.  It has no notion of these really.

It picks the biggest square by width though, I think, maybe.

*** Bug 3286 has been marked as a duplicate of this bug. ***

see bug http://bugzilla.icculus.org/show_bug.cgi?id=3286 for other input and ideas