Others that might be of interest
Facebook Notifications comes in handy for those who must update their Facebook status NOW, or check what other people have been saying to them.
Typinator. This is also a huge timesaver. Typinator is a text expander. You type an abbreviation, and it replaces it with a word, a phrase, HTML code, or an entire block of text. It also autocorrects common misspellings in any application. For example, if I type “.ew” (without the quotes), it replaces the text with my work email address. If I type “.ep,” it replaces the text with my personal email address. I also use it to type "http://www." from just "htt". It's not cheap at €20, but I think it's been worth it. See Lifehacker's Guide to Text Expansion for more ideas on how this can be useful.
Menu shortcuts are supposed to provide quick access to frequently used menu commands. Honestly though, how many shortcut keys do you know by heart? KeyCue helps you to use your Mac OS X applications more effectively by displaying a concise table of all currently available menu shortcuts. It's helpful, but not great value at €20. The aim is that over time, you will automatically remember frequently used shortcuts and start working more efficiently. One for developers, Visor brings up a terminal window with a simple keypress (by default it's ^^). The system menu icon can be hidden, and it makes sense to as it's really a set-and-forget item. Free.
I'm still making up my mind about these
Butler is another launcher, like LaunchBar, that extends to more things, like easily controlling iTunes from the keyboard. There's a long article praising it, but I need to spend more time with it to tell. There's a free trial, but to use it permanently costs $20. iKey is an automation utility, a program that creates shortcuts to accomplish repetitive tasks. At the simplest, this can be creating a keyboard shortcut to open a commonly-used app (such as ⌘-Alt-W for Word), but can also create standard replies to emails, and other things. Michael Hyatt loves it, but I expect I'll live without it, given I'm already using LaunchBar and Typinator.