Less known aplications - What do you use that you can share?

[variant]

I know several very usefull small aplications that not many people seem to know of.. here are two of them:

unclutter - hidese the mouse pointer after a short delay.

and

ddcxinfo-knoppix - probes your monitor for all supported modes.

also

feh - outstanding image viewer which can be used to set the background in windowmanagers such as fluxbox, it allso makes true transparancy possible.

[kkubasik]

i don't know if it is really a little known product, but nagios is simply the best network monitoring system i have ever encountered.

[Dillinger]

The only thing I know of that might be close is abcde, its a cli ripping program.