One of my major objectives in 2010 is to improve the way in which my team provides help, guidance and understanding to the creative communities within Imagination. Whilst we are pretty good at providing processes and business services, tools to help creative people be more creative is more of a challenge.
I've spent a lot of time in 2009 looking at how SaaS and Cloud technologies will replace traditional business systems. It seems now that there is much to be exploited in terms of creative tools now as well.
A few things that I've picked up on so far:
Aviary: image editing (bitmap and vector) plus audio editing… all in a browser.
Google Building Maker: Google attempt to 3D model the entire planet.
HobNox AudioTool: Music generation in a browser.
Would be interested to hear of other sites…
mmitII 
Another one – Prezi – a very different take on presentation software.
And also http://www.sliderocket.com/, another presentation tool.
Another one – online TiltShift photos at http://tiltshiftmaker.com/