Memory Management

[Duane Morin]

Ok, I turn on my machine.  It immediately reports that 85% of my memory 
(1.2 gig) is in use.  What are the best tools for determining what's using 
all that memory?  I'm not running anything meaningful!

here's some "top":

 14:58:56  up 12 min,  3 users,  load average: 0.03, 0.20, 0.20
68 processes: 66 sleeping, 2 running, 0 zombie, 0 stopped
CPU states:  cpu    user    nice  system    irq  softirq  iowait    idle
           total    0.6%    0.0%    0.2%   0.0%     0.0%    0.0%   99.2%
Mem:  1292024k av, 1073548k used,  218476k free,       0k shrd,   22844k 
buff
        87992k active,             931516k inactive
Swap: 1831368k av,       0k used, 1831368k free                  909496k 
cached
                                                                                
  PID USER     PRI  NI  SIZE  RSS SHARE STAT %CPU %MEM   TIME CPU COMMAND
 2138 duane      9   0 24212  23M  1992 S     0.0  1.8   0:00   0 gconfd-2
 2069 root      16   0 53132  20M  6924 S     0.6  1.6   0:07   0 X
 2187 duane      9   0 17352  16M  9976 S     0.0  1.3   0:00   0 nautilus
 2197 duane      9   0 17352  16M  9976 S     0.0  1.3   0:00   0 nautilus
 2198 duane      9   0 17352  16M  9976 S     0.0  1.3   0:00   0 nautilus
 2199 duane      9   0 17352  16M  9976 S     0.0  1.3   0:00   0 nautilus
 2195 duane     15  10 15760  15M  9508 S N   0.0  1.2   0:00   0 
rhn-applet-gu

Whats with the 909496k cached?  What is that? 

Duane