Ha, interesting a Mac user. Interesting! With Phatch 0.2 we would like to offer better cross platform versions. So we need your feedback.
Could you send me your email in a private message? You have to click the top left combobox where it is saying select. The crop action is available in phatch 0.2 which release is already finished and stable but only available through bazaar:
bzr branch lp:phatch
I can email it to you if you want. Phatch 0.2 has many new features and I would recommend it strongly over Phatch 0.1