Playing a musical instrument helps - the technique is even called "tonguing" for some wind and brass instruments - but I would imagine that would strengthen or train you for little movements, flickers, tongue taps, that kind of thing.
If you want longer motions, I'd think you could devise a set of exercises for yourself, sit and do them while writing, or while browsing sites. As long as you either do it in the privacy of home or don't mind looking like a total twerp.
Even better...find a willing partner and practice your endurance on them.