well first of all you need to do whats also known as "rooting your pre" then type
mount -o remount, rw /
vi /etc/hosts.
once the file opens press i to enter insert mode and move your curson just below the last line with characters. ignore the lines with '~'. then type 69.63.181.104 talk.google.com
press esc to exit insert mode.
press x to save again you have to make sure u are not on insert mode. quit by typing :q!
mount -o remount, ro /
reboot
and then go to facebook and get your username from the account settings.
add account to messaging and bingo!
***well jason beat me to it!

+++Its nice to see how patches are created. . . good learning experience