So after getting taglib up and running I was able to implement a file scanner to scan your sdcard/hd/whatever to bring in music into gmmp.
The UI is super simple right now.. mainly because its 3:30 in the morning. Under the hood the scanner can accept multiple directories to scan, specific folders to ignore, and a flag to ignore folders with a .nomedia file in it. I also added an option whether the nowplaying screen gets the song info from the actual file or from the database. I plan on putting something in tomorrow that lets you choose what information is actually scanned and stored from the file, so for those who want to take the "minimum data stored" route.. you will be able to just store filenames and the rest can be scanned from the file when its being played.