There are lot of good advice on the net, but all of them was based on using gconf-editor. Turned out, gconf-editor sucks.
Okay, it is still beta or what, but it simply fails to load all .xml files up from ~/.gconf parent dir, which I don't feel as a technological challenge.
If you ever happened to delete/create/delete-again/create-again a few GNOME panels, and now you have only 1 panel on your desktop, the only thing uncertain, is its name.
Mine is "bottom_panel_screen0", and it is not in gconf-editor's list. To find it easily (meaning "few typing, less thinking") I set my panel's height to a crazy 149 pixel and did a full search on the ~/.gconf directory with some help from 'grep'. BUT, if you are to issue this command, wait about a minute or drink a coffee after setting that 149 in the panel properties. It needs 'bout a freakin' minute to get this data written back to file.
$ find ~/.gconf -name "*.xml" -exec grep 149 {} \;
Now you have the file, you can modify those values inside it. You may find that there are no values associated to certain parameters like 'unhide_delay', 'hide_delay'. Those parameters are set as default elsewhere, but you can still override them here.
You could edit the .xml file itself with your preferred text editor, but gconftool-2 seemed to be the nice way of modifying parameters.
4 parameters that matter:
enable_animations
If you set it to 'false' the panel will pop up in a fraction of a second. When it is true, the panel will appear animated. I like it set to false.
$ gconftool-2 --set /apps/panel/toplevels/bottom_panel_screen0/enable_animations --type bool "1"
animation_speed
Defines the speed of animations, if that is turned on. Possible values are: fast, medium, slow. If you set the parameter to some gibberish, the last settings stays active. If you have a slow video card, speed may seem sluggish.
$ gconftool-2 --set /apps/panel/toplevels/bottom_panel_screen0/animation_speed --type string "fast"
unhide_delay
If you placed your mouse cursor where the panel should appear, this is the amount of milliseconds the system waits before the panel pops up. This works even with disabled animation. I suggest to keep it high to avoid unwanted popups if your mouse cursor wanders to the activation area.
$ gconftool-2 --set /apps/panel/toplevels/bottom_panel_screen0/unhide_delay --type int 1000
hide_delay
If you moved your mouse cursor away from the panel, this is the amount of milliseconds the system waits before the panel disappears. This works even with disabled animation. I suggest to keep it low to make the panel disappear as fast as possible.
$ gconftool-2 --set /apps/panel/toplevels/bottom_panel_screen0/hide_delay --type int 200
