JAY TULEY You can add info through the MusicBrainz website, and you can added fingerprints with iEatBrainz. You have to enter in your musicbrainz log-in into iEatBrainz preferences before these features become available. MusicBrainz problem is not that it's missing obscure songs, it's that it's missing fingerprints, 50% of the songs in the database don't have fingerprints, thus the search again by tag info typically finds a match if your information is pretty close. If you match by that search, the fingerprint is added to the musicbrainz database, thus helping the missing fingerprints. Version 1.04 which is close to being ready, however might be delayed due me going to WWDC, will have a way to manually match songs by browsing through the MusicBrainz website.
(Version 1.0.3)