I'm very much with techgnome. I use a lot of LINQ to Object, and don't see LINQ to SQL as worthwhile at all; primarily because only MSSQL supports it; and it's typically the last database I'm programming for.

I use it to sort and aggregate a lot of data though. The aggregation is where it saves me the most time as I can select and aggregate a collection of objects in one statement. I also use a lot of lambdas too in my code.