Per our friends at RTL-SDR.com, there is now a live DVD downloadable which includes Ubuntu Linux 12.04 along with GNU Radio and other pre-installed SDR related programs. The necessary libraries for OsmoSDR, RTL-SDR and HackRF hardware are also included. The Live DVD is only available for 64-bit CPUs. Check out the release notes for more details.
You can find links to the direct download and torrents of the ISO at RTL-SDR.com.