You can pull your respective operator logos on your Nokia mobile screens.

For MOBILINK GSM logo:
Send command "MLOGO" to 300

My Logo:
Send MYLOGO(space)<style>(space)<text> to 300

Where,
style = 1..34,i,b,r
1..34 = font number
b=bold
i=italic
r=reverse

Example: MYLOGO 3bi Ahmad

Operator Logos:

Send OPLOGO(space)<Logo number> to 300

Example: OPLOGO 1148