Tools

Wireshark (Formerly known as Ethereal) is the world's foremost network protocol analyzer, and is the de facto (and often de jure) standard across many industries and educational institutions. 

TreeSize Free - every hard disk is too small if you just wait long enough. TreeSize Free tells you where precious space has gone to. TreeSize Free can be started from the context menu of a folder or drive and shows you the size of this folder, including its subfolders.

My Folders - tired of double-clicking in Explorer windows to access the same folders every time? You put some shortcuts on your desktop but they take too much space and are not accessible when you are running an application? Then My Folders is for you!

LINQ

Visual LINQ Query Builder - is a Visual Studio 2008 Add-In and designer that helps you create LINQ to SQL Queries in your application.

.NET

Resource Refactoring Tool - provides developers an easy way to extract hard coded strings from the code to resource files.

VisualSVN - provides simple way to manage changes to source code inside Visual Studio using Subversion.

General

JingProject - snap a picture of anything on your desktop, record video of what you do, or what you see.

Backup 

Cheap backup solution for your home computer or business (site, hosting).