is there any kind of sms lock or sms guard available for nokia n95? i got mumsms from somewhere, but it wasnt compatible with n95..

I dont know about locking sms in phone. But you may try this-

You can copy all of your sms and mms into your computer using MobileEdit software. This is available for free.

Mobile Edit

After you have copied your sms to PC you can delete your sms from your phone.