I use my phone right now for sshing into my home machines and getting analytics, benchmarks, error logs, making spot changes to files, editing users and groups, etc. If you have a smartphone with a foldout keyboard, you're set. The possibility of me being able to do this with urxvt and emacs running on the phone is just awesome. Interacting with postgres on the cli with my phone is a dream as well. Obviously writing out huge statements is a pain, but you're generally just running one liners through to find some info.