Echoing previous years, Apple.com has once again posted an easy, online way for iPhone 3GS buyers to check and make sure their local Apple Retail Store has units on hand.

Both 16GB and 32GB, black- and white-backed models are shown, with nasty red squares connoting sell outs and happy green circles, supplies on hand.

So if you're heading out to get your hands on an iPhone 3GS this weekend, give it a try, and let us know how it works for you.