How to categorically theme views? I have a site that has several pages that are just views (a blog page, calendar page, and similar).  I want about 50% of my views to collapse the right column.  Do I have to create a template for each individual view?  Is there any way I can give views 1,2 &amp; 3 a 3-column layout and give 4,5 &amp; 6 a 2-column layout?

Idea: is it possible to add my own custom displays for views and theme those?  Right now I have Page, Block, etc - could I have Page2column and Page3column?  Then I could make my changes in views-view--page2column.tpl.php and views-view--page3column.tpl.php, right?
You could do this with Context. Set the Context condition to be either path or view based (depending on what suits your site structure) and then have the Context reaction take care of block placement (presuming your sidebar will collapse if empty).