LINQPad - a free LINQ query expression tool
Can't wait for C# 3.0 and LINQ? Well you don't have to! Dynamically query SQL databases today in LINQ: no more struggling with antiquated SQL. Download LINQPad and kiss goodbye to SQL Management Studio: LINQPad supports LINQ to objects, LINQ to SQL and LINQ to XML—in fact, everything in C# 3.0 and .NET Framework 3.5. LINQPad is also a terrific learning tool for experimenting with this exciting new technology.
No installation required: LINQPad ships as a simple "click and run" self-updating 300KB executable. Instant LINQ!
Read more and download here...