No defragger can actually specify physical placement of the files on the platter. The file system and storage hardware are not directly 'aware' of each other, so a defragger work only within the realm of the logical disk; it's the drive controller that decides as to which physical blocks are actually used for writing the data. Logically contiguous files may or may not be physically contiguous (but they should be pretty close I guess). Remember, the physical drive is not 2 dimensional although that's what the drive maps show. The HDD consists of more than one platter and more than one surface (and read/write heads) for storing data; so any claims of a defragger being able to write to a specific part of the platter should be taken with a pinch of salt.

As for Diskeeper, I use the 2009 Pro edition currently, and it has defragged my non-OS 250GB drive even with only 6% free space without any problems; it was in auto mode as I usually run it that way. The current Diskeeper versions work in low space quite well.

WMV11 and Winamp. I find myself reaching for WMV more often. :-\

Diskeeper 2008 Pro for me! :up:
Easiest to use, and most 'invisible', yet delivers great results.