I'm sure there are more reasons than just this, but it may come in handy to those that run into a 500 server error after enabling new modules or content-types.
Open up your .htaccess file and comment out "Options +FollowSymLinks" by adding a # in front of this line. Save, upload, and refresh your page.
 
Additionally, forcing php5 instead of version 4 may help this. You can do so by adding
 
AddType x-mapp-php5 .php
AddHandler x-mapp-php5 .php
 
to your .htaccess file.

I use a neat semi-solution. Check your account settings @ evernote.com and look for your evernote email address. If you're not aware of this feature -- it allows you to send an email to an address you have been assigned; it will store that as a note in your evernote, setting the subject as the note name and the body as the note contents. If you assign this email address as a shortcut on your BlackBerry, you can hit that button to send a note to your evernote acct from your blackberry, and it's a hell of a lot easier than using browser and logging in to your account to send notes...

I'm sure there are great arguments for starting out with nothing but core modules, and I'm sure there are even better arguments for every installation having all 32 of your favorites. This post, however, will outline a handful of modules to extend a basic Drupal 6.10 package into something that ought to have everything a client's website will need. This includes hands-free SEO, dynamic blogging capabilities, URLs-that-make-sense, and a handful of others. This is ideal, in this designers opinion, for most website needs.

A current project has had me setting up a large database and community driven site for a client. We're using Drupal 6 because of it's stability, features, extensibility, etc., as well as its great user and community-contributed content. One of the key requirements of this site is the ability to search through large amounts of pre-existing data, most of which are in PDF format. Off to find a proper module for extending Drupal's core search..

You may have some basic functionality of htaccess for Apache 2 in Leopard, but you won't be able to have any of the useful features (files, filematch, mod_rewrite, etc). To enable an override of htaccess you'll need to edit 2 config files. Launch Terminal and....

sudo pico /etc/apache2/httpd.conf
(enter your password when prompted)

A quick note - if you need to connect to a Windows system (nt, xp, server, 2000, vista) via RDP, you may be a bit out of luck. The Microsoft remote desktop client for Mac is not universal and may not run on some more modern OSX systems. One alternative is to install TSClientX, a terminal services client for OSX. This is a nice app, but running under Darwine can be a pain sometimes when you need a quick connection. Try grabbing a copy of CoRD instead - http://cord.sourceforge.net/ - a free, fast, and seemingly stable RDP client.

In order to get wireless adapters working on a Mac (intel, 10.3+), you may run into the many problems I did... No driver support for OSX, bus won't recognize the USB dongle, etc.

Different adapters you might need to get installed:

• Linksys Wireless-G Adapter (WUSB54G)
• Linksys Compact Wireless-G USB Adapter (WUSB54GC)
• Linksys Wireless-N Adapter (WUSB600N)
• Belkin N1 Wireless USB2 Adapter (F5D8051)
• Belkin USB 2.0 Wireless N Adapter (F5D8053)
• D Link Wireless-G Adapter (WUA-1340)

After lots of struggling and following notes on other boards, here's a surefire way to get Dreamweaver up and running on a new system with the same preferences and site listings that you've already got (or have on a backup!)

Adobe Dreamweaver's remote connection setting, whether it's FTP, SSH, SFTP, etc., can be incredibly temperamental. If you're running other apps like messaging or torrents in the background, or basically anything sharing the network connection (this could even be an email attachment download or other passive activity), Dreamweaver can report "Unable to connect", "Connection refused", and/or a few other warning when trying to connect with your remote server.

Update - Chad P. pointed me towards a matrix that compares the Standard, Pro and Extended: http://www.adobe.com/products/acrobat/matrix.html