If you haven't heard of PLINQO yet then you're missing out. The CodeSmith guys have enhanced the hell out of LINQ to SQL, to name a few features:

• Entity Clone
• Entity Detach ** My favorite!
• Many to Many relationships
• Auditing
• Rules
• Performance Enhancements

In their own words:

• "In the time that LINQ to SQL has been available, we have been identifying ways to make LINQ to SQL better. We have compiled all of those cool tips and tricks including new features into a set of CodeSmith templates. PLINQO opens the LINQ TO SQL black box giving you the ability to control your source code while adding many new features and enhancements. It's still LINQ to SQL, but better!"

I've been using PLINQO for over a month now and I really like it. It does require a CodeSmith license... BUT you can get a license free!!! Check out the details here.

There's also a great review of PLINQO by Kevin Lawry here. Enjoy!