Xbox Live Messenger On Windows Live Mobile

[mkeith813]

I have searched and cant find anything that answers my question. I know that there are a couple of applications that let you view your friends gamertags and such but I was wondering if when I am signed on to Windows Live Mobile, is there anything I can do so My friends that are online can instant message me to let me know they are playing. I would just like my friends to be able to contact me from their Xbox while they are online (mainly because I dont have the many of their phone numbers or I would just text). Any help and already greatly appreciated.