Engage Iran by paying attention to Cuba instead

Like Andrew Sullivan, I loved this suggestion from one of his readers, in response to long-time engagement proponent's Roger Cohen's assertion that now is not the time:

The point is, what we hoped to have achieved by engaging with Iran has already occurred (partly by walking very softly during their election). Thus the aim of any talks now can achieve nothing but strengthening the legitimacy of the regime while before talks weakened it.

In fact, the best move I believe the president can make is talking, loudly, to Cuba. If you can disregard the legitimacy of the stolen election in Iran and push directly for more openness and economic prosperity in an equally adversarial country, there's your carrot and stick, without directly meddling in Iranian affairs.