We ran in to a number of usability issues:

• After submitting our registration, the page refreshed to a new, blank registration form. Nowhere did it mention that our information had been submitted, and as far as we could tell, we weren't automatically logged in.
• The getting started page recommends either adding an MP3 URL (no uploading directly to the service allowed) or dragging the ffffoundtape bookmarklet to your bookmarks bar. We didn't have a bunch of MP3 URLs sitting around so it was off to the Obscure Sound indie music blog to find some tracks.
• Invoking the bookmarklet on any page that has links to MP3 files exposes a little arrow that can be clicked to listen to the MP3. After that, another click is necessary to actually bookmark the MP3.
• The bookmark page is identical to the page to submit an MP3 URL, and no information is auto-populated.
• Once back on the ffffoundtape page, we were able to view the songs we bookmarked, and optionally remove them. That's it.
• We could create a playlist using a separate page. Once created, we were still unable to add bookmarks to that playlist.
• Eventually we went back to our profile page, and found the songs we had bookmarked. Only on profile and public all-tracks pages could we add music to a playlist. If we remembered to create a playlist first.
• Finally, we were able to view, enjoy, and share our playlist page.

Unless this service really takes a hard look at streamlining this process, it is probably not worth investing too much time in it. Besides the multiple steps required to bookmark and organize tracks, it appears the service may not even store the MP3s, preferring to play them from the original source web pages. We understand this may be an issue of liability, but it also means that ffffoundtape may eventually be rife with broken links. Also, there's no way of exposing the source page of the tracks unless you remember to cut and paste the page URL when creating the bookmark. Finally, there's no export option, hence no way of storing your carefully found list of tracks offline.

The upside is, if you just want to browse and add other ffffoundtape bookmarks to your own playlists, it's relatively simple. Even there, though, once a track is added you get redirected to your playlist page and must navigate back to where you were. However, you can add a cover art image to each playlist.

Our recommendation? Stick with last.fm, iMeem, blip.fm, song.ly, or even Tumblr. If you want a second opinion, check out SheGeek's post on ffffoundtape.