I know, I know, everyone's talking about usin LINQ to Entities instead of LINQ to SQL, but there's so much that simply doesn't work when using LINQ to Entities.
First off, if you need to run a stored procedure that has nothing to do with any of the entities you are working with, the Entity framework simply can't handle it.
Secondly, there's the lack of support for using Contains to mimic SQL's IN operator. (You can use the Contains method as the equivalent of SQL's LIKE)
The Entity framework does have potential and version 2.0 is something I'm really looking forward to, but what I'm saying is that it is just not fully developed to use in all of your applications yet.