Рекомендую ознакомиться с очень простой ORM CoolStorage.NET.

• Supports SQL Server 2000/2005, MySQL, IBM DB2, SQLite, MS Access
  
• Any existing relational data model can be mapped to CoolStorage objects with minimal effort
  
• All relation types are supported: One-To-One, One-To-Many, Many-To-One and Many-To-Many
  
• Completely typed object model (no type casts required)
  
• Full support for transactions, including .NET 2.0 TransactionScope
  
• Nullable columns can be mapped to .NET 2.0 nullable fields or any other value
  
• Delayed (lazy) loading of data to minimize database access
  
• Powerful and intuitive database-independent object query language
  
• Flexible event framework to intercept any event
  
• Identity (auto-increment) keys are supported for all database types
  
• Support for server and client generated Guid keys
  
• Sessionless data access
  
• Objects can be mapped to different databases, even across object relations
  
• Pageable object collections
  
• Extensive support for retrieving aggregate values on collections (count, sum, average, ...)
  
• Collections implement IBindingList so they can be used by controls (grids) as a data source
  
• Underlying database engine uses optimized and parameterized SQL queries. SQL injection is impossible
  
• Built specifically for .NET 2.0, taking full advantage of generics and nullable variables
  
• Raw SQL and/or stored procedures can be called on the underlying database without the need for a separate database connection
  
• Small footprint (less than 150 KB)

Использую у себя на сайте — жутко понравилась В профессиональной деятельности использую XPO от Devexpress, должен сказать, что CoolStorage.NET ей неплохой конкурент (да и халявный).