Glenn Block has an implementation of ForEach for IEnumerable:

  1: public static class IEnumerableUtils {
  2:   public static void ForEach<T>(this IEnumerable<T> collection, Action<T> action) {
  3:     foreach(T item in collection) {
  4:     action(item);
  5:   }
  6: }

Robert Shelton has an updated list of LINQ Providers.

Scott Hanselman is at it again with a smarter and possibly evil ToString extension method.  Here is his example usage:

public void MakeSimplePersonFormattedStringWithDoubleFormatted()
{
    Person p = new Person();
    string foo = p.ToString("{Money:C} {LastName}, {ScottName} {BirthDate}");
    Assert.AreEqual("$3.43 Hanselman, {ScottName} 1/22/1974 12:00:00 AM", foo);
}

Scott Hanselman goes into detail about how extension methods work.  Want the short answer?  It's all taken care of at compile time.

Bart De Smet just posted part 0 in his new series about pattern matching in C#.

Mehfuz's adds the ability to use the same property multiple times in the where clause of a query to LinqExtender.  That's a little confusing, so here is the example that he gave:

var query = from book in _context.Books
            where book.PublishedDate > someDate 
            and book.PublishedDate < someDate
            select book;

Doug Finke posts about using PLINQ.

Scott Hanselman's Weekly Source Code series edition 19 covers LINQ and More.

The ADO.NET team blog has a post about a Drawing Editor sample application that is based on the Entity Framework.

Very cool!  Roy Osherove shows how to convert anonymous types into IDictionary.