S B This is a *really* great product. ReSharper is like a tireless, intelligent (and detail-oriented) software development assistant. Many of the most sophisticated .NET developers won't work without it.
ReSharper can tell you about/suggest improvements/refactor VB/C#/ASP.NET/MVC code intelligently, and in surprisingly powerful ways.
ReSharper works as a plug-in to Microsoft's Visual Studio 2008 & 2010 and provides context help, direct navigation to class definitions, uses, specific symbols, etc., etc.
It knows VB and C# syntax and will flag and suggest syntax corrections, style changes for your style, code improvements, etc. etc. It will then easily make (or undo) the changes.
It flags who uses what, shows where the values of variables come from and go to , and handles interfaces, delegates, lambda expressions, and their corresponding implementations for modern dynamic paradigms.
For developers, it is the most sophisticated and effective Visual Studio 2008 and 2010 third-party tool available. And it just keeps getting better!
-S B