HDHacker is a stand-alone micro-utility that saves, visualizes, and restores the MBR (from a physical drive), the BootSector (from a logical drive) or any specified sector from any disk (even removable disks).

another one gdrive

allows to "mount" several "gmail drives"

It has a "set it and forget it" feature similar to Diskeeper, here based on "idle time" instead of "screensaver", and it can stop if the CPU goes over a certain threshold. Free, but it seems to use a little bit more of memory than DK. I think it can be recommended

defrag + visualization + allows you to set some most used files to the fastest sectors

useful tips

500,

"Google has published a rather interesting paper (PDF) regarding the failure rates of hard drives. The report examined 100,000 commercial hard drives, ranging from 80GB to 400GB in capacity, used at Google since 2001."