Hi, did you ever get an answer to how to apply a web part to a multiple WFE server farm?  Does one have to copy the dll to each bin directory?

Also, I am also getting the error message:
"...must be compiled with the AllowPartiallyTrustedCallersAttribute set to succeed"

Did anyone find a workaround for this? I have the following line set in my assembly file:
[assembly: System.Security.AllowPartiallyTrustedCallers()]

And my web.config has the following line:

<SafeControl Assembly="FooWebParts, Version=1.0.0.0, Culture=neutral, PublicKeyToken=645f96a346d0edda" Namespace="FooWebParts" TypeName="*" Safe="True" />

Any help would be greatly appreciated....