gordon,
Heck, D-backs F1 Brad Ziegler did it just a couple of weeks ago in the playoff against the Brewers.
Baseball Video Highlights & Clips | ARI@MIL Gm 2: Brewers score five runs in the sixth - Video | MLB.com: Multimedia
(Around the 20-second mark.)
Of course, the IITBTSB dogmatists will come up with some specious semantic argument that the balk was for "...failure to deliver a pitch without interruption after having made a move which committed him..." or some such nonsense.
But, in the real world, it's "a balk to second base".
It's not impossible, it's just really hard.
JM