I'm going to be slightly flippant and say the the bundled tools and little one liners built with them. A few examples from my .profile follow: Eject a volume:

I'm going to be slightly flippant and say the the bundled tools and little one liners built with them. A few examples from my .profile follow: Eject a volume: alias eject='hdiutil eject' Copy the working dir to the clipboard: alias cpwd='pwd|xargs echo -n|pbcopy' Show current airport status: apinfo='/System/Library/PrivateFrameworks/Apple80211.framework/Versions/A/Resources/airport -I' Use spotlight to search for a file: spotlightfile() { mdfind "kMDItemDisplayName == '$@'wc"; } Use spotlight to search file contents: spotlightcontent() { mdfind -interpret "$@"; } Display a man page in Preview: pdfman () { man -t $1 | open -a /Applications/Preview.app -f } I've a few others but they're less generic than the above. Also although the above were sitting in my .profile I probably yanked them from random parts of the inter-webs; in other words, I take no credit for them. EDIT: One more generic one I use fairly regularly: google() { python -c "import sys, webbrowser, urllib; webbrowser.open('http://www.google.com/search?' + urllib.urlencode({'q': ' '.join(sys.argv[1:]) }))" $@ }