I've used LINQ mainly to work on collection of objects. LINQ works wonderfully with object collections, removing the need of predicate functions in most cases.
I tried using LINQ to SQL a little while ago, but found it underpowered and clumsy. In particular I couldn't bring myself to use the SQL Database class designer. Maybe it does give intellisense on the database, but who needs it when you've got SQL?
Let me tell you though, it's certainly a good idea to learn more about LINQ, as the applications in the future should only increase.