MacOS – Can anyone recommend an app for creating flowcharts and diagrams

I'm seeking a Mac app for creating basic flowcharts and similar diagrams.

Google has been no help; I've followed dozens of links to apps that either don't exist anymore, I can't find any real reviews of, or that won't run on OS X 10.6.6.

What I'd really like:

• A simple and clean interface

• Basic shapes

• Automated connectors that stay linked as you move shapes around

• Inexpensive, preferably under $30 but definitely under $50

What I'm not looking for:

• Hundreds of shapes

• Default styles that have shadows and textures and such that I have to keep removing

• Dozens of amazing features that allow you to automatically map databases and draw UML diagrams from code and such (I'm looking at you, Visio) that I have to constantly navigate around to make a few basic diagrams

• A mind-mapping app with all the features such a thing entails, one that happens to also let you make basic diagrams

• A full-fledged drawing app where, once again, I have to maneuver around a whole bunch of features and options to get to the basic functions I need. (I have Illustrator, I love Illustrator, but it's crap for basic flowcharts and other simple diagrams.)

I wouldn't actually use it for flowcharts, but rather basic similar diagrams to show data flow between apps, information flow in a company or other places, that kind of thing.

I recently found out that the drawing portion of Google Docs actually does a pretty good job with the types of diagrams I need to create, but the UI is pretty poor and it obviously requires a constant net connection.