Lately I've been working around the lack of gapless playback on my 4G by joining tracks, converting them to audiobooks, and using ChapterTool with AudioBinder, but this is time consuming.
I did some googling, and it seems gapless playback simply involves a player reading tags that store the correct length for each audio file… or something like that. Apple apparently won't support the feature on older models, but it should be possible on them. Has anybody tried to edit their iPod's firmware to do this?