Gone are the days of creating paper prototypes – see ya paper and cardboard – now we have web apps and a short list of my 3 favorite prototyping tools!

Omnigraffle: Great cross-platform software tool for creating wireframes, and comes with an iPad version for prototyping on the go. Only available for Mac.
ScratchPad: It hasn’t publicly launched yet, but this tool is sort of the Pinterest of web design tools. Anytime you visit a website where you like the way a button looks, or how a headline is styled, or a call-to-action is placed, you can clip those elements and store them. When you’re re-designing your website or making updates, you can look back at all the smart design decisions you liked.
Pencil: This is an open-source, cross-platform tool for website prototyping, including mobile prototypes.
