SharePoint Project Structure

CompanyName.[TYPE].FeatureName
Company.Framework: Multiple .NET libraries or external libraries
Company.Sp.Framework: Sp extensions that are generic across solutions in .NET
Company.BusinessModel: business logic not UI
Company.ObjectModel: data object model not UI
Company.[SOLUTION] for *.wsp or webparts or features to GAC
Company.[SOLUTION]WebApp
Company.UnitTests