FORMICA  I have tried AppTrap, and it's OK. However, when compared with AppCleaner 1.2.2, the difference is STRIKING. AppCleaner does most of the things that all of the reviewers below ask for, it finds ALL of the files associated with the main app you are deleting — EVEN FILES THAT ALL OTHER SUCH APPS OFTEN MISS — it is totally unobtrusive and doesn't impact your CPU or memory AT ALL as far as I can tell, IT WORKS AUTOMATICALLY when you maybe forget to startup AppCleaner and just toss an app into the trash ITS SmartDelete CATCHES IT AND ALSO AUTOMATICALLY CATCHES ALL ITS ASSOCIATED FILES AND OFFERS TO TRASH THEM FOR YOU! And perhaps most amazing is that it is so superior to all other such apps but it too is FREE, FREE, FREE, FREE, FREE! If you don't believe me, just check out the comments and reviews on AppCleaner's MacUpdate.com (http://www.macupdate.com/info.php/id/25276) and VersionTracker.com pages (http://www.versiontracker.com/dyn/moreinfo/macosx/32740&mode=feedback). That level of user satisfaction is far, far higher than all other such apps, illustrating that people love it for all its capabilities and performance — not just its price (which, again, is FREE!).

When you try AppCleaner, set the preferences to "Protect launched apps," "Protect default apps," and "Enable 3D transitions," don't forget to turn on SmartDelete, then one-by-one select the "Applications," "Widgets" and "Others" icons at the top of AppCleaner's main window, and with each one select the "Options" menu (in the Menubar) then "Select All" to instruct AppCleaner to protect all those apps, widgets and other resources from being accidentally deleted, then you can uncheck one-by-one all the ones that you don't want AppCleaner to protect. Trust me, you'll love this app with it set this way! Enjoy!

(Oh, and BTW, I am in no way affiliated with the makers of AppCleaner — I don't even know them. I just LOVE IT when truly great software is made available for FREE, and I feel such magnanimous developers should be promoted whenever possible, even when it's a bit annoying (as this comment is because it's in another app's MacUpdate space).  
(Version 1.0.5)

DNELSON  Developer, can we have an update?  
(Version 1.0.5)

RGMENKE  Like many OS X users, I've lamented the lack of a deinstaller built into the OS. From the beginning I've used Deinstaller to remove demo or no longer needed apps. The process worked as long as pkgs were installed, otherwise they don't appear on the list. Then I stumbled upon AppTrap. Wow! Apple should pay the developer for the code and implement it now. The program loads as a Preference Pane an that's it. Anytime you drag an application into the trash AppTrap locates the associated files and deletes them as well. What could be easier?  
(Version 1.0.5)

JEFFNE SCHELIN  The best uninstaller in my opinion. Doesn't requires me to launch it at all. Big up to the developers.  
(Version 1.0.5)

GARRYCH  Nice tiny util. Very helpful  
(Version 1.0.5)

KZX72  This program (not Cleanapp, Appzapper, Appdelete etc) is the uninstaller Apple forgot...

Keep updating it!  
(Version 1.0.5)

ZO219  This is definitely a 5 star utility - a pref pane, actually. But it functions perfectly: behind the scenes, catching most everything I delete, asking if I want associated files deleted too. 99% of the time, I do. What a time and work saver!  
(Version 1.0.5)

ALGOS  I love this little prefpane. Helps just a bit to keep your system somewhat more clean. As said before, it only sometimes misses out on the fact that it is a Sparkle update.

I also would like something like an exception list, so that you never see the warning for specific apps.  
(Version 1.0.5)

TICE  Great little helper! Unless all others, this thingy ask to help, so you don't forget to get rid of that junk files when you trash an app.  
(Version 1.0.5)

DNELSON  After upgrading to 1.0.5, System Preferences gives me an error:

Could not load AppTrap

Is this version for 10.5 only or something?

I have 10.4.11.  
(Version 1.0.5)