Often I want to copy/paste a line from my bash terminal and re-run it. Rather than hunt for the $ and copy only the command, I set my ps1 to be a comment. Bash makes this hard so I use the : operator to create a NOP command, and ; to signify that a second command on the same line should be run.

my ps1 looks like this now:

    : [bbeecher@Iago workspace]$;

so I can now do something like this:

    : [bbeecher@Iago genomic]$;: [bbeecher@Iago genomic]$;ls

And just get the ls at the end.