Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_2_1 like Mac OS X; en-gb) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8C148 Safari/6533.18.5)
I had some consistently large backups and it turned out it was the local copy of my iDisk. Time machine sees the whole volume as 1 file so even if you only edit 1 small file, the whole volume gets backed up again. This is the same if u turned on filevault. I believe virtual machines are also the same. You will need to select any of these files to be ignored in time machine preferences