All you need to do to listen to the radio on your Streak is download the three .zip files found in the link below, unzip them, and copy the files inside to your Streak's SD card. From there, just install the two apps, and copy the other file to System/Bin in Root Explorer, making sure that the system can't overwrite the file.
Finally, just open up the Streak Radio app, hit "on," and open up Sprint FM Radio to enjoy.
[xda-developers] Thanks, Vijay!