LyricsDB is a lyrics searching plugin for foobar2000 (yet) player. Concept is simple: you install it in foobar2k's components folder and after that you will be able to import/export lyrics from/to the database (by right mouse button menu or hotkey). Once you download lyrics, it can be saved to the %LYRICS% (configurable) tag just by pressing the [ok] button in a preview window, so you can read it whenever you want. The database also has a web-interface, but it is not what all it is for, just for some checks and other mysterious reasons. You can use plugin without checking web interface at all.
It is also recomended to register your login to the database in foobar2k-> preferences -> Tools -> lyricsdb. It does not mean, that access to the database will be limited somehow, but information about lyrics'es source will be available to other users. So login is only used when you export lyrics, requests to the database are absolutely anonymous. Email is only used for password restoration, you can use adresses(at)like(dot)that(dot)su but it surely will cause delays while restoration.