On my site items sorted using the category menu item. When it displays the list of items it shows the entire items and lists them single file vertically. This is a major problem since on my site most of my items are 720x600 flash files. Is their any way i could display item previews using titles and 100x100 thumbnails and arrange them in a grid.

I figured out how how to make it show only thumbnails and titles but i still need to make these display in more then one column.

Edit your category
On the right-hand side under the Category item layout is the Layout grid
You can adjust the Columns here.