http://hackontest.org looks like a nice opportunity, so please get involved and see where it brings us. Note that it is not enough to suggest features and vote on them, someone would need to suggest themselves as implementors - each entry in the final competition will require 3 persons to work together for 24 hours to complete as much as possible of the feature.
The best team can win 5000 USD, whereas 2nd and 3rd get 2500 and 1000. In addition to this, all participants get a free trip to Zurich in Switzerland, where a 3 day stay (up to USD 1000) will be sponsored. This is from 23rd to 26th of September this year.
The link to the Tango entry.