I've never used an electronic tuner as I find them a bit too "accurate" for "in tune" tuning. I have E and A tuning forks secreted away in the depths of my instrument cases for the rare occasions I need them. Normally I tune by ear to an "in head" top E which seems to produce a fairly accurate approximation. More often though I tune to whatever fixed pitch instruments I happen to be playing alongside.
All that being said...I was admiring an Intellitouch in a shop window the other day for its compact and ingenious design! So maybe I'll yet be swayed!