Site Big Fat Prize (apparently in beta test) keeps, well, a big fat list of prizes, including prize value, links, and short prize descriptions. A lot of the prizes covered are the ones typically covered here - space prizes and technology innovation prizes. There are plenty of others.
I see a lot of business plan competitions, for example (including space business plans like Lunar Ventures or the Space Frontier Foundation's Business Plan Competition).
There are categories for space and science prizes, but those are empty. Since the link I gave at the beginning of the post has plenty of space prizes, I imagine they'll fill in these categories at some point. They do have a lot in the lists for invention and technology, and they even have a separate section for The X PRIZE Foundation's prizes.
I don't know exactly where they're going with the site, but it has potential. I hope they can fill in the missing spots, get the blog going, and add some more database lookup capabilities (for example, searches based on not just prize category but amounts, past and future events like prize registration timeframes, and other useful criteria). I have all sorts of other ideas that might work for the site ... who knows how much work it would be to implement, though.
One prize they list that I should mention is the Kavli Prize, which is like the Nobel Prize in that it looks back at past achievements rather than giving an incentive for a future achievement. It includes three $1,000,000 prizes every 2 years (starting in 2008). The fields are Astrophysics, Nanoscience, and Neuroscience. The way they bring together those 3 diverse fields is "The prizes focus on the science of the greatest physical dimensions of space and time, the science of the smallest dimensions of systems of atoms and molecules, and the science of the most complex systems, especially living organisms." It sounds pretty symmetric now!
I'll give the Astrophysics prize a bit of special attention by adding their description of its scope:
The Kavli Prize in Astrophysics will be awarded for outstanding achievement in advancing our knowledge and understanding of the origin, evolution, and properties of the universe, including the fields of cosmology, astrophysics, astronomy, planetary science, solar physics, space science, astrobiology, astronomical and astrophysical instrumentation, and particle astrophysics.