The joy of shell
Writing about web page http://ask.slashdot.org/askslashdot/08/11/05/2027234.shtml
There's a discussion going on Slashdot entitled "(Useful) Stupid Unix Tricks?". (Clicking the 'Get more comments' button at the bottom of the page a few times makes more of the discussion visible.) I love discussions like that because I nearly always pick up something useful.
A useful trick that occured to me this morning was to combine && with a kdialog yes/no prompt:
kdialog --yesno "are you sure?" && do_stuff
Of course stuff which is really useful on one Unix-like OS is sometimes useless on another. I work on Linux, but sometimes need to do something the multi user Solaris boxes such as mimosa or primrose etc and occcasionally get tripped up by differences. Though I've found changing my shell on Solaris to bash instead of the default tcsh and adding /usr/local/gnu/bin/ to the start of my $PATH helps!