There was a freeware program out there called nameswap that was changing the last name to first and vice versa. By doing that it was also forcing the contacts to reduce their size by compressing/defragmenting them. When i first used it, the size was reduced to the 1/3 of the original but after some time it started getting bigger again... I think you can find it on ass on the software download section. Though i don't remember where exactly cause i post through wap.