angelfish
You can use powerpoint to do mockup screens, and even 'fake' them actually
working.... eg. by clicking a certain area and the 'jumping' to simulate
something happening.
The only downside - is that powerpoint will 'anti alias/smooth' your screen
grabs of actual computer software.
Cheers
TAJ Simmons
awesome - powerpoint backgrounds,
http://www.awesomebackgrounds.com
free powerpoint templates, tutorials, hints, tips and more...