11 Powerful Firefox 3 Add-ons... Plus more

Some really awesome extensions listed from this blog

11 Powerful Firefox 3 Add-ons That Can Replace Standalone Applications

I would like to honor this list by adding a couple more extensions.

DownThemAll DownThemAll (or just dTa) is a powerful yet easy-to-use Mozilla Firefox extension that adds new advanced download capabilities to your browser. Replaces external download managers.

ScrapBook is a Firefox extension, which helps you to save Web pages and manage the collection. Replaces offline web browsers.

Adblock Plus Blocks advertisements. Replaces ad blockers.

LinkChecker Check the validity of links on any webpage. Replaces link validaters.

FoxTorrent Download torrents right in Firefox! Replaces bittorrent clients.

Plain Old Webserver Turn the web on its head with the Plain Old Webserver (POW), which adds a server to your browser. Replaces external web servers.

IE Tab Embedding Internet Explorer in tabs of Mozilla/Firefox. Replaces opening Internet Explorer.

Honorable mentions:

MeasureIt Draw a ruler across any webpage to check the width, height, or alignment of page elements in pixels.

ColorZilla Advanced Eyedropper, ColorPicker, Page Zoomer and other colorful goodies.

Sameplace Talk with your contacts from GMail, Jabber, Twitter, MSN, Yahoo!, ICQ, AIM. Replaces Instant Messengers.

ScribeFire for blogging

ScribeFire is surprisingly really good, 100x better than Blogspot's blog editor.

It's hard to believe I've gone so long without using Scribefire for blogging. Now I can worry less about properly formating my content and more on the actual content.

Software Virtualization Apps

Freeware

Sandboxie
Sandboxie intercepts changes to both your files and registry settings, making it virtually impossible for any software to reach outside the sandbox.

Short Review: I've been using this one for years, it has it's quirks, but it's probably the easiest to use for newbies.
Positives: Easy to install new apps, easy to manage, configurable, light on resources.
Negatives: Occasional have nag screens, some features disabled, not all programs will run properly.
USB Portable: Yes (there's a portable wrapper for it)
Liscence: Free for personal use.
System Requirements: Windows 2000, XP, Vista, Server 2003

SVS Altiris
Altiris® Software Virtualization Solution™ (SVS™) is a new way to use software. By placing applications and data into managed units called Virtual Software Packages™ (VSPs™), SVS allows you to instantly activate, deactivate, or reset applications, to completely avoid conflicts between applications, and to remove them cleanly without altering the base Windows installation. Say goodbye to "DLL Hell" and "Registry Rot".

Short Review: Easy to use, the layer idea is unique.
Positives: Easy to install new apps, easy to manage, configurable, light on resources.
Negatives: Requires a free liscence to run. Aquired by Symantec (no telling how long this will remain free/updated)
USB Portable: No.
Liscence: Free for personal use.
System Requirements: Windows 2000, XP, Vista, Server 2003

JauntPE
JauntePE is a simple utility that is designed to help you
attempt to run non-portable applications in a portable
manner. Its two main features are the redirection of registry
modifications into a portable registry file and the re-
direction of special directory file system modifications
into equivalent portable directories. Both of these options
are available on a per-application basis, so it's possible
to create completely standalone portable "packs" of
otherwise non-portable applications.

Short Review: None.
Positives: Easy to install new apps. Doesn't require admin rights.
Negatives: Buggy. Doesn't catch everything. Kind of slow for certain apps. No longer supported.
USB Portable: Yes.
Liscence: Free for personal use.
System Requirements: Windows XP (only tested)

Shareware

ThinApp (formally Thinstall)
Run any version of virtually any application on a single operating system without conflicts. You can even run multiple versions of the same application. Plug VMware ThinApp, formerly known as Thinstall, into your existing management infrastructure and accelerate your software development and desktop deployment. Deliver and deploy applications more efficiently, more securely, and more cost-effectively with agentless application virtualization.

Short Review: None.
Positives: Apps are self contained. Doesn't require admin rights.
Negatives: For virtaulization it tracks changes to the computer.
USB Portable: Yes.
Liscence: Commercial
System Requirements: Windows XP

These I have heard of these as well but have not tested any of them.

Prayaya
Ceedo.com
u3