you can cut strips straight..it just takes practice, and maybe a non skid ruler...they make a ruler with rough patches on the bottom..called creative grids..if you can only afford one, get the 4.5 x 18.5
[url]http://www.creativegridsusa.com/products.cfm#rectangles
most LQS's sell them also.
or you can get o'lipfa, it has an actual lip on it, to help line up and keep in on the cutting mat.
http://www.save-on-crafts.com/olliprulbr5x.html
you can use a coupon, and get it from Joanns and maybe michaels crafts sells them.
the gizmo your referring to, the machine? save your money..heard more bad than good.