I noticed something "eats" the memory on my ASUS WL-500g Deluxe router with whiterussian rc4/jffs2 installed.

Free shows ~25 megs used, I was afraid of some mysterious memory leak:

root@OpenWrt:~# free
              total         used         free       shared      buffers
  Mem:        30584        25680         4904            0         2416
Swap:            0            0            0
Total:        30584        25680         4904

Consulting /proc/meminfo shows the real (hopefully) memory usage, and then I noticed that free doesn't show "cached":

root@OpenWrt:~# cat /proc/meminfo
        total:    used:    free:  shared: buffers:  cached:
Mem:  31318016 26353664  4964352        0  2482176 14577664
Swap:        0        0        0
MemTotal:        30584 kB
MemFree:          4848 kB
MemShared:           0 kB
Buffers:          2424 kB
Cached:          14236 kB
SwapCached:          0 kB
Active:           3676 kB
Inactive:        13004 kB
HighTotal:           0 kB
HighFree:            0 kB
LowTotal:        30584 kB
LowFree:          4848 kB
SwapTotal:           0 kB
SwapFree:            0 kB