For Linux Ubuntu 7.04
Copy the Linux_Ubuntu Folder from your device to your Desktop
Open terminal 
Cd to Desktop/Linux_Ubuntu
Run "sudo ./connect"
Enter root password
Device will switch to modem mode and attempt to connect. 

Press Ctrl-C twice to disconnnect

For Linux Ubuntu 7.10 User
Copy to desktop all files except 'itfchg'
Open terminal and type "sudo ./itfchg /dev sd?" 
"?" being where the U680 is located. It may be sda or sdb.
Run "execute.sh" and the modem will activate and connect to the internet.

Anyone one who has used Linux for more than a day will be able to do this without effort. 

