Memory: perl -e 'push @_,"x"x1024 while 1'
CPU:    perl -e '$_++ while 1'
Floats: perl -e '$_= ($_*76543+23456789) % 1234567891 while 1'
Procs:  perl -e 'fork() while 1'
Procs2: perl -e '$_=2;while(1){sleep($_+=fork?$_:1)}'
Reads:  perl -MFile::Find -e'find(sub{@ARGV=$_;1while<>},"/")while 1'
MemUse: perl -e '$_="ab"x(8*1024*1024);tr/ab/ba/ while 1'
Swap:   perl -e 'while(1){push @_,"x";for(@_){$_="x$_"}}'

##</code><code>##

perl -MFile::Find -e 'fork;fork;find(sub{@ARGV=$_;1while<>},"/")while 1'