VirtualMode and DataGridView
The new DataGridView control allows you to run the control in VirtualMode. This is a feature if you will (sounds like a nightmare to me) where one can show thousands or even millions of rows in a grid and avoid the performance\memory hit.
Long story short, you tell the control to run in VirtualMode and then, as the user scrolls down the grid (as cells are painted\displayed) you can handle the CellValueNeeded (provide a value for a cell when it's rendered versus holding all the data in memory) and CellValuePushed (if you want to support editing) . I only hope developers carefully consider what they are doing when they use this feature. Or, for that matter, carefully considering presenting thousands or millions of rows in a tabular fashion at one time.
If I am ever on a project where I need to display thousands of rows, or millions, please shoot me, or better yet, shoot the customer ;-)