ActiveLock is an open-source copy protection, software licensing framework for all development enviroments supporting COM+ architecture. Core DLL available in VB2008 and VB6. Samples in C++, C#, Excel/Access VBA and keygens in PHP, ASP.NET available.
Very nice piece of software I used to protect my old VB6 products as well all new .NET products. A bit tricky at the start but once you put it in place it does the job.