@Abstract allows you to abbreviate the content of a field in a Notes document. What I find cool is that it can also work on Rich Text fields. Now, @Abstract is very powerful and can allow you to do some interesting transformations with information in a field, but for the purposes of exposing some abstract information in a view, we'll just use the simple stuff.
In order to maintain good performance in your application, you shouldn't use @Abstract in the view itself. Instead, create a new field on the form in question in order to capture the abstract information. You can then refer to this field in the view column. Let's say you want to add this functionality to a document library. Open the 'Document' form and add a new field called "BodyAbstract". This should be a computed text field. The formula for this field would be something like:
@Abstract( [TextOnly]:[TrimWhite]; 1000 ; "" ; "Body" ).
As used here, this will capture the text of the "Body" rt field, trimming out whitespace and grabbing the first 1000 characters (Check out the help file to see how you can enhance @Abstract with additional keyword parameters).
In the view, in order to allow the user to decide whether or not the abstract should be visible for a particular document, I made the "Subject" column categorized, then included the abstract in a regular column. Here's what it looks like in design mode:
And here it is in action:
@Abstract is useful for many purposes, and this simple technique exposes just one of those. I think this idea makes sense for a lot of document-based repositories and as a bonus is really easy to implement.