What's the point of the var keyword?

Without the var keyword it becomes possible to accidentally create a new variable when you had actually intended to use an already existing variable. e.g.

name = "fred";
   ...
Name = "barney"; // whoops! we meant to reuse name

Update: There are two related questions here, actually: 1. Why do I have to declare variables at all? 2. What use is "var" in a language that makes you declare variables?

The answers to (1) are numerous, and can be found elsewhere for this question. My answer to (2) is below:

As other commenters have said, LINQ uses this for its anonymous types. However, LINQ is actually an instance of a more general problem where the type of the right-hand side of an expression is either unknown to the programmer, or is extremely verbose. Consider:

SomeGeneric<VeryLongTypename<NestedTypename>> thing = new   
SomeGeneric<VeryLongTypename<NestedTypename>>();

Verbose and error-prone, right? So now they let you do this:

var thing = new SomeGeneric<VeryLongTypename<NestedTypename>>();

By reducing the duplication of information, errors are eliminated. Note that there aren't just typing errors, here: it's possible for the type of the left-hand expression to be mistyped in such a way that the compiler can silently cast from left to right, but the cast actually loses some property of the rvalue. This is even more important when the types returned by the rvalue may be unknown or anonymous.

I understand the need for var and it serves it purpose great. Having no keyword and just defining variables on the fly with no type is scary. Your hurting the next guy who has to maintain your code or yourself if you need to rework the code you haven't touched in over a year. I am not sure that is a door that should be opened in C# and I hope it isn't as var is already causing readability issues when being over used when it is not necessary.

Almost every .net 3.5 example I am seeing lately has all variables defined with var.

The arguement I make is that it really sacrifices readability for the sake of saving keystrokes when it is over used. For example:

// What myVar is, is obvious
SomeObject myVar = new SomeObject();

// What myVar is, is obvious here as well
var myVar = new SomeObject();

The problem I see is that people are using it everywhere... for example:

// WTF is var without really knowing what GetData() returns?
// Now the var shortcut is making me look somewhere else when this should
// just be readable!
var myVar = GetData();

// If the developer would have just done it explicitly it would actually
// be easily readable.
SomeObject myVar = GetData();

So the next arguement will be, just name the function better...

var weight = GetExactWeightOfTheBrownYakInKilograms();

Still don't know what is coming back. Is it an int, decimal, float, weight object, what? I still have to waste time looking it up... need the intellisense crutch to save the day from my lazy programming. Maybe include the return type in the function name. Good idea, now using var has saved us nothing except making all my functions have real long names.

I think people are just over using var and it is leading to lazy programming which in turn leads to harder to read code. Everytime you type out the keyword var, you should have a good reason why you are using it instead of being explicit.