Here are a couple of patches for adding support to Spicebird. I am using jar.mn but you could make a similar change to chrome.manifest instead.

changeset: 5156:88581f5c06f8
branch: minimizetotray
user: Sunil Mohan Adapa <sunil@synovel.com>
date: Thu Feb 18 18:52:26 2010 +0530
summary: New overlay for Spicebird based on TB

diff --git a/collab/extensions/minimizetotray/chrome/content/collabOverlay.xul b/collab/extensions/minimizetotray/chrome/content/collabOverlay.xul
new file mode 100644
--- /dev/null
+++ b/collab/extensions/minimizetotray/chrome/content/collabOverlay.xul
@@ -0,0 +1,42 @@
+<?xml version="1.0"?>
+<!DOCTYPE overlay >
+<overlay id="minimizetotrayMailOverlay"
+ xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
+ <script type="text/javascript" src="chrome://minimizetotray/content/core.js"/>
+ <script type="text/javascript" src="chrome://minimizetotray/content/mail.js"/>
+ <!-- the key short cut -->
+ <keyset id="framework-keyset">
+ <key id="extensions.mook.minimizetotray.key.menuitem"/>
+ </keyset>
+ <!-- toolbar button -->
+ <toolbarpalette id="framework-toolpalette">
+ <toolbarbutton id="extensions-minimizetotray-button-minimize"/>
+ </toolbarpalette>
+ <!-- file menu item -->
+ <menupopup id="file-menupopup">
+ <menuseparator id="MinimizeToTrayMenuSeparator"
+ insertbefore="file-importexport-separator"/>
+ <menuitem insertafter="MinimizeToTrayMenuSeparator"
+ id="extensions.mook.minimizetotray.menuitem.menuitem"/>
+ </menupopup>
+ <!-- tray popup -->
+ <popupset id="framework-popupset">
+ <popup id="extensions.mook.minimizetotray.traypopup"
+ onpopupshowing="window.extensions.mook.minimizetotray.loadPopupMenu();">
+ <menuitem id="extensions.mook.minimizetotray.traypopup.restore"/>
+ <menuseparator
+ id="extensions.mook.minimizetotray.traypopup.restore.separator"/>
+ <menuitem label="&getMsgButton.label;"
+ oncommand="goDoCommand('cmd_getMsgsForAuthAccounts');"/>
+ <menuitem label="&newMsgCmd.label;" accesskey="&newMsgCmd.accesskey;"
+ oncommand="MsgNewMessage(null);"/>
+ <menuitem label="&addressBookCmd.label;" accesskey="&addressBookCmd.accesskey;"
+ oncommand="toAddressBook();"/>
+ <menuseparator id="extensions.mook.minimizetotray.pupup.close.separator"/>
+ </popup>
+ </popupset>
+</overlay>
diff --git a/collab/extensions/minimizetotray/jar.mn b/collab/extensions/minimizetotray/jar.mn
--- a/collab/extensions/minimizetotray/jar.mn
+++ b/collab/extensions/minimizetotray/jar.mn
@@ -5,6 +5,7 @@
chrome/content/calendarOverlay.xul (chrome/content/calendarOverlay.xul)
chrome/content/calender.js (chrome/content/calender.js)
chrome/content/core.js (chrome/content/core.js)
+ chrome/content/collabOverlay.xul (chrome/content/collabOverlay.xul)
chrome/content/download.js (chrome/content/download.js)
chrome/content/downloadOverlay.xul (chrome/content/downloadOverlay.xul)
chrome/content/mail.js (chrome/content/mail.js)
@@ -176,6 +177,6 @@
chrome/locale/zh-TW/common.properties (chrome/locale/zh-TW/common.properties)
chrome/locale/zh-TW/prefs-window.dtd (chrome/locale/zh-TW/prefs-window.dtd)

-% overlay chrome://collab/content/collab.xul chrome://minimizetotray/content/mailOverlay.xul
+% overlay chrome://collab/content/collab.xul chrome://minimizetotray/content/collabOverlay.xul
% overlay chrome://collab/content/collab.xul chrome://minimizetotray/content/minimizetotray.xul
% override chrome://minimizetotray/locale/brand.dtd chrome://branding/locale/brand.dtd

changeset: 5159:f07fb146751d
branch: minimizetotray
user: Sunil Mohan Adapa <sunil@synovel.com>
date: Fri Feb 19 12:43:36 2010 +0530
summary: Improve the overlay

diff --git a/collab/extensions/minimizetotray/chrome/content/collabOverlay.xul b/collab/extensions/minimizetotray/chrome/content/collabOverlay.xul
--- a/collab/extensions/minimizetotray/chrome/content/collabOverlay.xul
+++ b/collab/extensions/minimizetotray/chrome/content/collabOverlay.xul
@@ -18,10 +18,8 @@
</toolbarpalette>
<!-- file menu item -->
<menupopup id="file-menupopup">
- <menuseparator id="MinimizeToTrayMenuSeparator"
- insertbefore="file-importexport-separator"/>
- <menuitem insertafter="MinimizeToTrayMenuSeparator"
- id="extensions.mook.minimizetotray.menuitem.menuitem"/>
+ <menuitem id="extensions.mook.minimizetotray.menuitem.menuitem"
+ insertbefore="file-close-item"/>
</menupopup>
<!-- tray popup -->
<popupset id="framework-popupset">
@@ -34,8 +32,6 @@
oncommand="goDoCommand('cmd_getMsgsForAuthAccounts');"/>
<menuitem label="&newMsgCmd.label;" accesskey="&newMsgCmd.accesskey;"
oncommand="MsgNewMessage(null);"/>
- <menuitem label="&addressBookCmd.label;" accesskey="&addressBookCmd.accesskey;"
- oncommand="toAddressBook();"/>
<menuseparator id="extensions.mook.minimizetotray.pupup.close.separator"/>
</popup>
</popupset>