Sorry bit late to post this but this possible (not 5 bit address scheme).
In Wire.begin() if you don't write anything it will take the default address(i,e 127, 0x7F) but if you give any other address which does not conflict with other device it takes that address(if you send like Wire.begin(0x05) and then run the nick gammon scanner sketch making another arduino as master that the one which has been programmed with 0x05 will give the address 0x05. I have the screen shot i will post it some other time. )
Thanks everybody for their valuable input
Regards
Niladri