Ram Defraggers

Am considering installing Fast Defrag Standard 2.02.90. (as per links attached below).

1) Has anyone had any personal experiences with this software??
2)Any alternative software suggestions for Ram Defragging??
3)Any possible/probable bad side effects from using a Ram Defragger??
4)I have a fair amount of software [Norton SystemWorks, Spybot, Ad-aware, Hijackthis, CWShredder, Zonealarm pro 4.0, Spywareblaster, SpywareGuard, RegSupreme 1.1(registry cleaner), Jv16 Power Tools, Nero CD Burner], installed. Any risk of software conflicts??


Second unrelated question. What does a registry defragger do??
How is a registry defragger different than a registry cleaner?? Or is it different?? If a registry defragger is a useful tool, any suggestions which is a good one??

http://www.majorgeeks.com/download.php?det=2475

http://www.amsn.ro/index.php?action=2

Thanks in Advance for any assistance