I dunno what OS you use, but I find AudioPod works great for submitting my iPod-listened tracks to last.fm. It's java based, so it should be cross platform. There's an AudioPod+ version as well. The only caveat is that you must submit all your 'Pod (or in your case, 'Pone) tracks before you start listening with your computer based player, or you'll trigger last.fm's spam protection, and it will reject the submissions.