Maybe you are like me mostly using either C# or VB.NET and not developing full time so the syntax is not there in your memory to easily convert back and forth between the languages. You might have found a nice snipped of csharp code and want it in VB.NET.
Here are some options I've used.
Here is a free online converter: http://www.kamalpatel.net/ConvertCSharp2VB.aspx
The free converter can also be downloaded and run offline.
Another online converter can be found here:
Another option is to use the free Open Source .NET IDE SharpDevelop http://www.icsharpcode.net/ that has functionality to also convert code. Look at Tools>Convert Buffer C# to VB.NET and Convert Buffer VB.NET to C#.