ADO.NET, getRows...?

Is there a method that works like the old ADO-"GetRows" in ADO.NET?

If I want to use disconnected data, then must I use a dataset or is it possible with a datareader as well?

What does the "dataAdapter" actually do?

Which is the fastest way to access data from a database (SQL 2000)? Is it to use the datareader och a dataset?

Thanks in advance!!!!