In fact, you can hack it so that you can open many Yahoo Messenger windows with different user names. And you have to hack the registry to do that.

1. Open Registry Editor by click Start -> Run menu, enter regedit in box and then press Enter key.
   
2. Drive to registry path: HKEY_CURRENT_USER \ Software \ Yahoo \ pager \ Test.
   
3. Create a new DWORD value by right click on empty space on right panel, and then click New -> DWORD value menu.
   
4. Replace the original value to Plural.
   
5. Modify its value data by double click Plural value, replace the original value to 1 and then click OK button.
   
6. Close Registry Editor and then restart your computer.
7. Based on my test, I could open four accounts simultaneously in four different Yahoo Messenger windows. But I think it could be open more than that.

To bring it back to standard configuration, just remove Plural value or give it with 0 value data.

(article no: 0152)

2. After it has downloaded, double click downloaded file Proxi_v1.4.dmg (file name may vary) and then after dmg file has opened double click Proxi.pkg icon.

3. After installation process has done, open Proxi program (By default, the location in your Application folder).

4. In Proxi window click iTunes Monitor (you can find it at Component section) and click then drag it to Triggers section.

5. If Proxi window don’t show up click Proxi’s Window menu then click Proxi Editor menu.

6. Click iTunes Monitor in Triggers section and then check Trigger when track changes value.

7. Then click Task button and click Insert Task – AppleScript menu.

8. Click AppleScript in Tasks section then choose Run custom AppleScript option (or if you’ve create the file you may choose Run as existing AppleScript option then browse to your Script file), and type this script below.

set messageText to ""
set SkypeIsRunning to 0
try
    tell application "iTunes"
        set trackName to name of current track
        set trackArtist to artist of current track
        set trackAlbum to album of current track
    end tell
    if not trackArtist = "" then
        set trackArtist to " sing by " & trackArtist
    end if
    if not trackAlbum = "" then
        set trackAlbum to " from album " & trackAlbum
    end if
    set messageText to "Listening > " & trackName & ", " & trackArtist & trackAlbum & " <"
end try

set commandText to "SET PROFILE MOOD_TEXT " & messageText
tell application "System Events"
    set SkypeIsRunning to count (every process whose name is "Skype")
end tell

if SkypeIsRunning > 0 then
    tell application "Skype"
        send command commandText script name "test"
    end tell
end if

9. And remember this trick can apply as long as Proxi software is ran, to make it easy just run it at login with set it from its Preferences, you can access it from Proxi – Preference menu and then check the Start at login option.

10. Close your Proxi window and then open iTunes and try to play a song.

11. If you run it for the first time you will asked to allowing Proxi and AppleScript run for Skype.

12. And your iTunes track information has set as Skype Status.

(source: http://www.johnwilker.com)
note :
On Skype 2.7 or above, they had including this ability. Just open Skype Preferences menu and check Show iTunes song in my mood message in Advanced tab. But with this trick at least you can customize your mood message.

(article no:0095)