- Capacity This should reflect what you are using the mp3 player for. If you want it for short term gym use , go for a small widget with solid state memory . If you want make "music collection on the move " a reality , go for a hard drive based jukebox . 1gb=250 songs.
- Size Portable is a very broad term. THe large hard drives are certainly pocketable but, when it comes to use for physical activities , they are trumped by the tiny , durable "sports " players.
- Compatibility Make sure your computer has firewire or USB 2.0, otherwise you could be in for a long wait when transferring files(syncing).
- Battery life Hard Drive jukeboxes will last around 10-15 hours, solid state mp3 player last longer .