How do you create an icon in the taskbar using GTK+???

[Fixman]

How do you create an icon in the task bar using GTK+ for GNOME?

[Compyx]

Assuming you mean you want your application to have an icon next to it's name in the task bar (like for example Firefox has), this might help:
http://library.gnome.org/devel/gtk/unstable/GtkWindow.html#gtk-window-set-icon-from-file

Since you haven't provided any information on what language you're using and your problem description is somewhat vague, this is the best I can come up with.

HTH

[Fixman]

No, I mean in the right taskbar, as aMSN does

[duff]

http://library.gnome.org/devel/gtk/2.11/GtkStatusIcon.html

[MicahCarrick]

I think "taskbar" is unclear. The "Notification" area is the same as "System Tray" in windows lingo. That is the area in the lower-right corner of Windows and often the upper-right corner of GNOME where running programs can have a icon (such as Gaim, Rhythmbox, etc.).

If you want to put an icon there, you'll want to use a GtkStatusIcon (http://library.gnome.org/devel/gtk/2.11/GtkStatusIcon.html) to do so. More information about the standard for notification area icons is available at FreeDesktop.org (http://www.freedesktop.org/wiki/Specifications/systemtray-spec?action=show&redirect=Standards%2Fsystemtray-spec)