gmusicbrowser

gmusicbrowser works if you replace post.audioscrobbler.com with turtle.libre.fm in /usr/share/gmusicbrowser/plugins/audioscrobbler.pm

There is also a unofficial plugin (a quick hack of the last.fm plugin in gmusicbrowser 1.0.2) made by user kabniel, which can be downloaded from https://dl.dropbox.com/u/1114536/code/librescrobbler.pm
Add it to ~/.config/gmusicbrowser/plugins/