My iPhone is packed with crisis coping aids, such as:
~ music
~ photography
~ Apps, e.g. mood trackers & meditation guides
~ website links, e.g. PsychCentral
~ contact list for my support team
~ games (for sublimating)
~ sketch pad
~ note pad
... etc

I have all the same things on my computer and iPad at home, but the iPhone goes with me everywhere--and my crises are more numerous when I'm "out there" in the world.

Good luck with your DBT work.

Roadie