Also, File Browser idea is good as well.
JSR-75 provides
Java Developers access to Mobile Phones' File System and PIM (Personal Information Management) Database. You can do a lot in this area, other than File Browser.
Just check out
this link.
The Final Year Project depends on your ideas. If you want to go in for emerging "techy" stuff, then SIP will be a good idea. JSR-75 will be a little easier than SIP (to my belief, again, these stuff are personal opinions).
But what
you should understand is, Final Year Project will not be easy anyway. If it was, then whats the point of having a final year project after all those years of study? Hit the ground with
determination and you will succeed.
Best of luck !