dTunes, a new app by Richard Shearman, lets you grab all the free music you'd like, downloaded straight to your iPhone using some magic to combine SeeQPod's streaming .mp3 service and Jonathan Misurda's useful Safari Download Plugin.
Download dTunes (available via Cydia now on the MMi repo), and once installed, tap the magnifying glass or the Search Seeqpod button. dTunes will bring up a window with Seeqpod in it - simply search for the music you'd like, and when found, tap the song.