On my XP Pro system I use MemInfo only to display free RAM not to defrag it.
I am with DavidR in the need to defrag RAM.
Me too on both, except I've never needed to reboot XP to reclaim memory. Windows XP with a 1GB pagefile and 1GB RAM have always done a good job for me at managing memory. My Windows 98SE system works best if rebooted daily.
BTW, I slowed meminfo's refresh rate down from its default of one second to five seconds. That reduced its CPU from 0.3% to one fifth of that on my 600 MHz XP box. (Sorry, watching it rack up 10 seconds of CPU time every hour bugged me.)