What about an android port?
Neat and technically possible, but unlikely to be worth the massive effort - probably 9-12 months of full-time work. Playscii's UI is mouse and keyboard centric, it's coded in Python which isn't easy to get running on Android, and it uses regular OpenGL instead of OpenGL ES (the mobile flavor).
Well I think that $5 would be a great price for a portable version and hopefully make the development time worth it. Few other developers I really like do that. Desktop versions free, mobile costs. Either way hopefully you decide to, would enjoy doing this to and from work on public transportation.
Edit: Also, if you could port it as is, with the ability to zoom in and out that would be awesome. Though I would use this on my phone, on my tablet as is would be fine. Check out SunVox if you get a chance. Has one of the best interfaces for this sort of thing on mobile.