*important* make sure you know what format you made the recordings in (mp3/aac). just look on the right hand side of the track progress bar while recording live (see screenshot below) in this example it is recorded in aac. tune in will automatically record in mp3 format usually.
so, once you have the recording saved, connect your phone to pc via usb. navigate to your tunein folder, usually mnt/sdcard/tunein. find the recording you want to listen to/copy, it will look something like this; 20111131-074437. copy it over to your pc.
now, just add .aac or .mp3 to your file name. (.aac or .mp3 depending on what it was recorded as)
good? done! that's it. you now have your tunein recording as a readable file on your pc. if you want to remove ads/tracks in the recording, use an audio editor to do so. i use this; http://www.nch.com.au/splitter/index.html
it should be noted that for recordings 50mb+ it can be hit or miss with this method. so try to keep your recordings below about 2 hours long...