Provided that you have rooted your cool Google phone and preferably run a class-6 microSD card, you should once in a while backup your SD-card:
BACKUP:
mount -t vfat /dev/block/mmcblk0p1 /sdcard
mount -t ext3 /dev/block/mmcblk0p2 /system/sd
cd /system/sd
tar cvf /sdcard/ext3.tar *
RESTORE:
mount -t vfat /dev/block/mmcblk0p1 /sdcard
mount -t ext3 /dev/block/mmcblk0p2 /system/sd
cd /system/sd
tar xvpf /sdcard/ext3.tar