Some tools I use...
This might or might not be of interest to folks, but I'll share anyway. There are a number of third-party apps I use that many people might not know about. Some of you might already use them, others might not. Here are a few of them with links and a brief description. I suggest you check them out.
1Password: This manages (and creates) passwords and auto fills them from any browser. Syncs across computers and devices. Extremely handy way to auto-enter information and maintain security. http://agilewebsolutions.com/products/1Password
A Better Finder Series: This makes it super easy to batch rename files in complex ways. For example, you can easily change a bunch of files that are named "FirstName LastName.jpg" to lastname-firstname.jpg" and more. http://www.publicspace.net/ABetterFinderSeries/
Adium: This is a multi-client instant messenger program. http://adium.im/
AppFresh: This will automatically alert you to updated software. http://metaquark.de/appfresh/
AppZapper: This will delete applications and all of their associated files. http://www.appzapper.com/
Audio Hijack Pro: Super easy way to capture and record audio from any source, such as a video stream or iTunes. http://rogueamoeba.com/audiohijackpro/
Automator: A super-easy way to create automated workflows. http://www.apple.com/downloads/macosx/automator/
Default Folder X: This utility allows you to set default open/save dialog box folders and simplify the navigation of open/save dialog boxes. http://www.stclairsoft.com/DefaultFolderX/
Dropbox: This is a Web-based tool for synchronizing folders across the Web and devices. You can create a drop box on your machine and create a Web interface so that others can easily upload files to it. Sort of like FTP but easier. http://getdropbox.com/
Komodo Edit: This is a cross-platform text editor, like TextMate, TextWrangler and BBEdit. This is particularly useful for PC users. http://www.activestate.com/komodo_edit/
LittleSnapper: This is a great screenshot utility and manager. That is, it will take and manage your screenshots, including full Web pages with Flash on them: http://www.realmacsoftware.com/littlesnapper/
MacFuse: This is an add on that allows you to use Mac OS X file handling on non-native volumes (i.e., Windows, etc.): http://code.google.com/p/macfuse/
NeoOffice: This is an open source version of Microsoft Office, including a database that can link to SQL, like Access. http://www.neooffice.org/neojava/en/index.php
OmniGraffle Professional: This is an awesome flow chart and wire framing tool. I can't speak highly enough about it: http://www.omnigroup.com/applications/OmniGraffle/ Be sure to also check out their other offerings.
OpenOffice.org: Like NeoOffice: http://www.openoffice.org/
Path Finder: This tool replaces your standard Finder. One great attribute (and there are many) is that when you copy a file, it copies the entire path: http://www.cocoatech.com/
Perian: This is an awesome QuickTime components utility to make all kinds of video files work on the Mac: http://perian.org/
RipIt: Great DVD ripper: http://ripitapp.com/ (Also check out MacTheRipper (http://www.macupdate.com/info.php/id/14414), VisualHub (no longer downloadable) and Handbrake (http://handbrake.fr/) for ripping and encoding video.)
Saft: This is a Safari add on that remembers your open Tabs and lots, lots more: http://haoli.dnsalias.com/Saft/index.html
SuperDuper! This is a data backup and copying utility. Has saved my butt many times: http://www.shirt-pocket.com/SuperDuper/SuperDuperDescription.html
SWF and FLV Player: This will play SWFs and FLVs directly, and will also tell you their dimensions: http://mac.eltima.com/freeflashplayer.html
Switch: This is audio encoding software. Takes your audio and makes them MP3s. http://www.nch.com.au/switch/ (Max is another: http://sbooth.org/Max/)
TextSoap: This is a multi-step text cleaner. In other words, you can link multiple find/replaces in one step and clean up text automagically: http://www.nch.com.au/software/index.html
Transmit: The best FTP client out there with drag-drop interface, droplets and more: http://www.panic.com/transmit/
TweetDeck: A great Twitter client with multiple panes for direct messages, searches, etc.: http://tweetdeck.com/beta/
WireTap Studio: Very similar to Audio Hijack Pro: http://www.ambrosiasw.com/utilities/wiretap/
Xmarks: This will synchronize your bookmarks (and passwords) across platforms and computers. So, your FireFox and Safari bookmarks will always be in sync.: http://www.xmarks.com/
YouSendIt: This is a way to e-mail somebody giant files.: http://www.yousendit.com/
OpenID: This isn't an application, but a service that will unify different profiles under one ID. For example, you can link several Basecamp accounts under one OpenID. http://www.myopenid.com/
Regular expressions: This isn't an application either, but rather a way of doing complex pattern-matching search and replace. Let's say you want to search "Josh is a buffoon" and change it to "What a buffoon Josh is!" You could do that by searching "(Josh).*(buffoon)" and replacing it with "What a /2 /1 is!" It's easier to demonstrate.
Concatenation in spreadsheets: Also not an app, but a way to take columns of data and turn it into XML. More here: http://www.hatchomatic.com/2009/02/18/simple-xml-template/
Batchgeocode: Need to get lat/long for a place, or a bunch of places?: http://www.batchgeocode.com/
There are more, but this is a pretty good list. I hope it's helpful to folks.