Abel Avram posted about a pure .Net port of SQLLite3 to C# over at InfoQ

"Noah Hart has ported SQLite3 to C#. While the first port is slower than the original, the project opens the way
for SQLite to be used in .NET managed projects without using P/Invoke or unsafe code…"

"Many products, including Adobe AIR, contain and use SQLite. Probably the best use of C#-SQLite is for Silverlight
projects …"

The ported version is called C#-SQLite.