Here are some of the responses I got:
TextExpander — Create text “snippets” that expand to complete words, phrases, and more.
MailActOn — Move around and apply rules to email messages using the keyboard.
MailTags 3 — Add medadata to your email messages to make it easier to organize, sort, and find.
FastScripts — Trigger scripts using keyboard shortcuts.
Jumpcut — Provides “clipboard buffering” — that is, access to text that you’ve cut or copied, even if you’ve subsequently cut or copied something else.
Keyboard Maestro 5.3.2: Work Faster with Macros for Mac OS X — Trigger custom actions and macros using keyboard shortcuts.
DragonDrop, from ShinyPlasticBag — Lets you set down what you’re dragging, leaving you free to find your destination without worrying about keeping the mouse button held down.
Noodlesoft | Hazel — Watches whatever folders you tell it to, automatically organizing your files according to the rules you create.
Alfred App — Launch apps, browse iTunes, perform web searches, and more using your keyboard.
f.lux — Makes the color of your computer’s display adapt to the time of day, warm at night and like sunlight during the day.
emory When it comes to working with many sources of data, learning to write shell scripts and basic text manipulation is probably the biggest time saver you can have. more important than ruby/python/java/AppleScript.
jxpx777 Exploring and learning what’s available and possible with things like Automator and the Services menu, smart folders, etc. Learning about metadata in general to reduce fiddly busy work like using create dates rather than tagging w/ dates.