This was the most useful program I had under Ubuntu and I miss it greatly; evernote is bloated and complicated. Is there something like tomboy for the mac? Bonus points for iphone sync.
I suggest you use Tomboy Notes until you find an alternative.
There are tons of simple note-taking applications on OS X. A popular iOS variant is Simplenote. Its website lists well known, sync-able Windows and Mac OS X applications. I suggest you try JustNotes and Notational Velocity first.