WIREFRAMING APPS

alts to omnigraffle or the thing i made:

reviews etc

http://www.snipe.net/2010/02/wireframes/

this cool app you can draw wireframes in it - and output sketchy style, so client dosn't think its a design. - online and offline app avail, etc

http://iplotz.com/

this one too

http://www.balsamiq.com/products/mockups