I mean I want to see the difference in the size..LOL. Cause I want to experiment something..Heheh..
Well you could always look at the maximum upload memory size defined for each entry in the arduino core file 'boards.txt'.
You can see that the Uno has a value of:
While the Duemilanove has a value of:
The difference is the size of the bootloader memory size protection options used to hold the two different bootloaders used by these too boards.