Personally, I hate how command-A in Quicken is "Show Accounts" instead of "Select All." While there is no menu item for "Select All," you can assign your own key commands to Quicken menu items (or change and delete the existing ones) by holding the Command key and selecting the menu item. This hint is documented by Intuit on their website for Q2003, but I have used it in Q2004 as well. It's documented but not as widely known as it should be!
[robg adds: I had no idea this was possible; it also works fine in Quicken 2002 ... yes, it's been a while since I upgraded my copy of Quicken!]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20030909013820737