File selection box

[sumner pathway net]

I'm interested in making the GUI offered by gtk really easy and fast
for the user, and I have thought of a few possible improvements to the
file selection box.

Has anyone ever seen the file selection box on the Macintosh?  It has
a little window at the top that lets you jump upwards to any directory
above you.  For instance, if you're currently in 

/usr/local/share/vim/syntax

The box would let you go to:

/
/usr
/usr/local
/usr/local/share
/usr/local/share/vim

It's actually a little menu-box, like the menus that aren't in a
menubar.  I just used a Mac a couple of days ago and found that it
made the file selection box a lot easier to use. (of course, the Mac
had plenty of other problems, but this was pretty neat) If the home
directory ~ were added, it'd be even cooler.  Would adding this to the
gtkfilesel widget be useful?  I would love it, and it could be done
without making the file selection box any larger just by changing the
"Directory" label into such a menu (that popped up when you pressed it).

Some related ideas:

Clicking on the Directory label moves to the / directory;
right-clicking moves to .., center clicking moves to ~.

Menus tied to the center and right buttons that are
user-configurable.  (not as useful, IMO, and possibly just unneeded
bloat, but while I'm tossing ideas around...)

Allow wild cards in the text-entry box; entering "*.c" would make it
so only .c files are shown, etc.  Would require some thought as to
how to open files that have a * in the name, but the advantages
outweigh the disadvantages (IMO) and most computer users are used to
the * meaning this. (The ? too, things like [] and {} as used by tcsh
and other Unix shells are less common).

Allow a smaller file-selection box that has the files and directories
in one box and is half the width of the current one; directories come
before files on the list, and when there's a wildcard mask (as above)
all directories are shown.

Do any of these seem like things that would be accepted into gtk if I
wrote them?  Or are they too high-level?  

Is there a well-defined way for the user to override the default
filesel, colorsel, etc?  

TTFN,

  Sumner