I've left this page here in case you have it bookmarked or find it via a link from somewhere else, but the plugin is dead and no longer linked from my front page.
This plugin only worked for Foobar2000 0.8. Another person updated it for 0.9 but it seems that doesn't work with newer 0.9 versions either. The Foobar2000 developers & forum mods have also added "banned" the plugin since they dislike the way it works. So, even if I wanted to update it, there wouldn't be much point.
(I no longer use the plugin and only just (October 2008) got around to updating to Foobar2000 0.9 as 0.8 worked so well and I didn't want to re-make my config for 0.9.)
If you want the feature that this plugin provided then you should try to convince the author of your chosen Foobar2000 user interface (e.g. Default User Interface, Columns UI, etc.) to add it. It should be very easy to add as it's just a window flag. Integrating the setting ito a UI component would also remove the (completely reasonable) objections the devs/mods had about this plugin. Maybe some of the replacement UIs already have such an option; I don't know.
Alternatively, buy a pair of 1920x1200 screens and you probably won't mind the space used up by the extra taskbar button. :-) :-) :-)
Remove Taskbar Button Plugin for Foobar2000
This Foobar2000 plugin removes Foobar2000 from the Windows taskbar, even when its window is visible.
This is a bit of a hack but it seems to work, more or less. You may still see FB2K appear on the taskbar briefly before the plugin removes it but it shouldn't clutter things up for more than a second or so. I think to do it properly would require a change to FB2K itself (unless the plugin turns the FB2K window into a ToolWindow, which I tried but found rather ugly). Note that this will not work if you're using an alternative taskbar/shell.
Update: In fact, there is a better way to do it, without modifying FB2K, which Jon Potter (of Opus fame) told me about. I might implement it one day but it's a fair amount of coding effort when I'm happy enough with the current, simple method.
A much more ideal solution would be for the Foobar UI DLLs to provide an explicit option for this. They can control whether the taskbar icon appears in a much better way than the hack that this plugin uses but, until then, it's better than nothing!
Foobar 0.9 version
(UPDATE: As stated in the OBSOLETE section above, the plugin (even this version) no longer works with newer versions of Foobar2000.)
Thanks to Roshan Jansz for letting me know.
Download (includes C++ Source)
Foobar 0.8 version
By request, here is the version which turns the window into a Tool Window. Source is included in the main zip, just commented out.
Copy foo_notaskbar.dll to your Foobar2000 Components directory and then restart Foobar2000. You should no longer see Foobar2000 on the Windows taskbar. (You'll still see it in the system tray, assuming you've set the tray icon to show at all times.)
If you want to turn off the plugin just delete the DLL from the components dir. There is no configurable on/off switch. Sorry.
0.1 (26th September 2004)