You can't set a variable when you insert a widget if that's what you mean... You can set the amount of comments in the settings > module > blog settings but then all the recent comments widgets will use that setting.

If that's not what you want, then try to modify the module and add a few extra widgets...

I think Andre means the same as there happens in the blog module. Normally the amount of comment you want to show is set with a ModuleSetting. That's the easiest way for doing this.

Indeed. You can change the items per page, but also the total number of items in the blog widgets. But maybe he wants to insert multiple widgets into his website, each with a different amount of items?

Oh I just figured out that you weren't explicitly talking about the blog module. Other modules with recent comments widgets probably also have a setting for the number of items...