Rtlsdr

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sudo apt-get -y install libxi-dev
mkdir src
cd src
git clone git://git.osmocom.org/rtl-sdr.git
cd rtl-sdr/
mkdir build
cd build
sudo apt-get install cmake libusb-1.0-0-dev checkinstall
cmake ../
make
sudo checkinstall
sudo ldconfig
sudo cp rtl-sdr.rules /etc/udev/rules.d/
sudo /etc/init.d/udev restart

rtl_test
                                                                                                                                                                                                                                                                              
and then to get gqrx, the graphical scanner, go to
http://sourceforge.net/projects/gqrx/files/latest/download

to install gnuradio, do the following commands:
sudo apt-get install libaudio-dev

sudo apt-get -y install libxi-dev

sudo apt-get -y install libfontconfig1-dev libxrender-dev libpulse-dev \
swig g++ automake autoconf libtool python-dev libfftw3-dev \
libcppunit-dev libboost-all-dev libusb-dev fort77 sdcc sdcc-libraries \
libsdl1.2-dev python-wxgtk2.8 git-core guile-1.8-dev \
libqt4-dev python-numpy ccache python-opengl libgsl0-dev \
python-cheetah python-lxml doxygen qt4-dev-tools \
libqwt5-qt4-dev libqwtplot3d-qt4-dev pyqt4-dev-tools python-qwt5-qt4

or maybe all you need is this:
http://www.opensecurityresearch.com/files/gnuradio_rtl-sdr_bt5r2_bundle_v0.1.tar.bz2
from this webpage
http://blog.opensecurityresearch.com/2012/06/getting-started-with-gnu-radio-and-rtl.html