I dunno about Tagscanner--might be harmless and great--but I'm leery of any free downloadable program that wants to help me "organize" my MP3s.
Seems that due to the Napster/Kazaa problem of a few years back, the record industry scrambled to reign it in and hastily came up with a lot of schemes and "free" software downloads. Bundled in the download is often a deeply embedded bit of spyware that goes out on the net to check the actual wav form of a file against a database of pirated music, and tattle on you, in addition to "helping" you name your untagged music files.
Now, I'm not suggesting anybody on PM has anything to be concerned about--uh huh, yeah, right-- but even if you're an upstanding citizen who's 100% squeaky clean in this department, such spyware can be a resource hog and a huge waste of bandwidth, not to mention a backdoor for some future exploit. One such organizer that was bundled with my .mp3 player (MoodLogic) wanted to connect to the web for every one of my microphone-recorded mouth call tracks, trying to identify and rename them. Not finding these, it would hang my system for some unknown reason. What a pain in the neck.
Incidentally, in both Windows and OSX, I find it's possible to very simply rename the mp3 file by highlighting it a directory, and overwriting to whatever your heart's desire (with Windows, you don't want to zap the .mp3, .wav or .wmv or whatever extension, though). Admittedly, you won't erase or change anything else in the ID3 tag this way though.
Happy New Year!
LionHo