Recommendation for a small DBMS for use as a local datastore for a small .net app

I am looking for a local, relational datastore for a .net application.
The datastore should ideally behave as a basic database with SQL for data retrieval and definition and transaction capability. It should not need a server and be easy to redistribute (i.e. only need a dll in the app to access a single db file).
No support for access over the network is needed. It should provide a .net data provider and support linq-to-sql, as the purpose for this app is too deepen my skills in .NET 3.5.

Any ideas / recommendations for libraries / technologies that worked well for you in similar circumstances?

From stackoverflow

• SQLite, maybe?

• SQL Server CE

• If you want Linq to Sql then you must use a variant MSSQL. SQL Server Compact edition is the most light-weight database that supports Linq to Sql but you may want to go for Express edition instead since it supports stored procedures and other nice things.

  Einar : From what I gather, you can use any DB with a Linq to SQL provider. See http://kubasik.net/blog/2009/02/09/using-linq-to-sqlite-providers-updated/ for a Linq to SQL provider for SQLite.

  Rune Grimstad : If I understand it correctly they use Linq to Entities there, not Linq to Sql. Not that the difference is huge... :-)

• Sql server Express