Is there a way my DAL classes can be re used across different databases ?

I know some technologies (Linq and EF) support rapid development, I appreciate this feature but I also want to keep my DAL Code reuse able in different database.

A Simple thing that come to mind is use of Oledb with inline SQL queries, Is there a more elegant way ? please guide me. I am just considering 2 things.

1. support to 4 most commonly used databases (SQL Server, My SQL, Access, Oracle).
2. Rapid development support.

Thanks