The Carmack 100kft Micro Prize - Armadillo Aerospace - Currently one launch attempt is scheduled, the Proteus 7 sounding rocket, at the Tripoli Rocket Association's Black Rock Desert high power rocket event.
NASA Tournament Lab: Open Innovation On-Demand - OSTP Blog discusses NASA's prize and open innovation work, including the recent NASA Tournament Lab announcement of the winner of a contest to create ideas to automate detection of craters.
Competition Shines Light on Dark Matter - OSTP Blog
Team Agreement – For Review - Sample Return Robot Challenge
HeinleinPrizeTrust - YouTube - The Heinlein Prize Trust YouTube channel has some newly uploaded videos of the 2011 Heinlein Prize Award ceremony to Elon Musk.
The 2010-2011 academic year's AIAA Design Competitions include a Low-Cost Access to Space Booster Aircraft, an Orbital Debris Removal Spacecraft, and a Propellant Depot Design and Analysis of Economic Benefit.
The next 2 links are from the Science in School - Competitions page.
Entries wanted for the 2012 European CanSat competition - ESA
Explore the dynamic high-energy Universe – competition for secondary students - ESA - The competition is open to secondary students from "ESA Member States and Cooperating States, Russia and the USA".
A Busy Summer Looms for Masten - Parabolic Arc describes a highlight in a visit to Mojave.
Google Lunar X Prize Appoints New Senior Director - Parabolic Arc presents a press release on the new director of the Google Lunar X PRIZE.
Altius Selected as Finalist for the 2011 NewSpace Business Plan Competition - Altius Space Machines (link from RLV News)
We-Are-Space Video Contest Finalists Now Online - Space Frontier Foundation (link from Space for All)
NASA/Etsy Space Craft winner's work on Atlantis - Space for All