Here's another product that is worth investing in if you work often with fondant:
A fondant cutter!
I feel like I'm advertising for Wilton products, but seeing as how they pretty much have a monopoly on cake decorating supplies, so be it. I love this thing! It makes perfectly straight lines which all have the same width. Very important if you want you cake to look neat (as in, not sloppy). Also SO much faster and easier than measuring. This fondant cutter works as an embosser too. Definitely must-have tool when working with fondant!