inspired by What one-liners do people actually use? i wrote a little utility for bash:

addhist.pl:

#!/usr/bin/perl
use strict;
use warnings;
my @lines = <>;
pop @lines;
my $hist = join '', @lines;
my $history = "$ENV{HOME}/.oneliners";
$hist =~ s/\A\s*\d+\s+//;
open my $fh, ">>", $history or die $!;
print $fh $hist;
close $fh;
[download]

# put these in your .bashrc
alias addhist="history 2 | addhist.pl"
alias readhist="history -r ~/.oneliners"

$ perl -wle'something short and useful'
$ addhist
[hours or days later...]
$ readhist
$ !! # will get you your last saved oneliner from above
[download]

i can't get this to work with "oneliners" that have more than one line, though...