Rnds is a project mainly written in Ruby, it's free.
Generate ASCII noise
Generate printable ASCII noise
Display usage:
$ rnds h
Usage: /home/drichert/bin/rnds [optional: <length>] [optional: an (alphanumeric only)]
Generate default (16 chars atow) length noise string:
$ rnds
m|RG]!`lP^WJ-ORa
Generate 66 characters:
$ rnds 66
9-8H:q0yPa}ltPx!R4@,lU9/X%=|(/#Al{^53rb*eos1aa'4vg_wo_Oq/Qh+X!J?kC
Generate 13 alphanumeric characters:
$ rnds 13 an
EIaCqVbex7qxk