I've posted a few helper classes, that I've created by myself or based on some others source code.
There are also a few classes from other authors, that I am using in my applications without or with minor changes.
Below I will list the links to their classes:
Configuration:
C#/.NET Command Line Arguments Parser(by the way, it was the first class in C#, that I included to VB solution)
Custom app.config -load configuration settings from an external file(alternatively see Reading a config section from an external file in ASP.NET 2.0)
ADO.NET helpers:
Export Data to CSV ( Excel ), C# Samples (alternatively
C# class library for exporting data to CSV/Excel file - The CodeProject could be used)
ASP.NET
Common Web Page Class Library - Part 2 By Eric Woodruff - Detecting changes in data controls in ASP.NET web forms
(Consider to use Dirty Panel Extender (ASP.NET AJAX) - The Code Project instead)
To manipulate with URI/URL I am using my own UriHelper class as well as UrlUtils class, downoaded from Mono(some early version can be viewed here). I've just changed class to public,and commented references to internal methods.
I've noticed that some of my helper classes are not searched by Google, that II hope that these links will help Google to crawl it:
DataBinderHelper class..
My StreamHelper class
My ArrayHelper class.