Sometimes you will see it up on the post, or not.
Also, you can try for Princeton Homebrew's google group. Joe at Princeton homebrew gets them in about once a month and whenever he sends out the email blast they sell out in minutes (so have a Paypal acct and reply specifically to which one you want in the email--e.g., you reply "I will take pack B," instead of "any is fine." I pop into Princeton Homebrew and sometimes he has ECY, sometimes not. Its a crapshoot. But the best thing, especially if you are local or within a decent driving time of Trenton, is that when summer comes around Joe gets ECY in but won't ship it. Thats usually the best time to stock up on ECY from Princeton Homebrew if you can't get it from love2brew or aren't quick on the email blast.
Good luck!