You may have seen my previous post on Learn Emacs: Fit your Workflow. I've improved the function to bring up a full frame eshell buffer, and restore back to previous window configuration with less code. Previously I was using some complex keyboard macros to try to restore my specific usual frame setup. This rewritten function will work for any frame setup.
I owe this tip to magnars' emacs configuration.
More on registers here
Emacs 24.3 was released today. If you're on OS X, the easiest way to check it out is by downloading a build from EmacsForMacOSX.
As for what's new in Emacs 24.3, in true Emacs fashion, we can ask it directly.
M-x view-emacs-news
If you're using Smex M-x will suggest other view-emacs-* commands.
So next time you're wondering about how to do something in Emacs try asking it directly.
M-x info-emacs-manual
Will view the Emacs manual as info pages.
The visor I refer to is a feature of TotalTerminal.
I use Quicksilver all the time. Despite its bugs, I prefer it to any of the other launcher type programs that exist. Nevermind the fact that it is more powerful than most of those other programs (Alfred, LaunchBar, etc). The single feature that got me hooked is the ability to bring up the Quicksilver prompt with a single keypress. I have it set up to use the command key.
Other tools like Alfred won't do this (though it does have the command key double tap).
Over the years I've found myself needing a quick way to measure some slow code. Whether I'm looking at a 100 line function or a 10 line controller action, sometimes I just need some quick print statements to determine which part of the code is slow.