Update: Welcome Digg.com and Kotaku readers. Updated below w/ tips on only getting notifications when new Xbox inventory is available. Congrats to the many that have read this and purchased your Xbox 360.  Thanks to Bensbargains.net for their Xbox tracker service and Sightmax.com for sponsoring hosting for this site.

Here's a fool-proof way to get notified when Xbox 360's are available for online ordering- no online auctions required.  I've tested it personally- and I should receive my premium system in time for Christmas.  There may be other tactics, but I hope it works for you. Happy Holidays!

Step One: Bookmark Bensbargains Xbox 360 Tracker
There are lots of sites that purport to track Xbox 360 shipments.  Bensbargains is the best IMO.  They're tracking all the major and a number of minor sites that are carrying the Xbox 360.  The site is legit and updated about every minute. Even better is their history list so you can see who got what in and map our trend patterns.

This is great if you want to check every minute.  They also have convenient RSS feeds, but again this requires you to sit there and wait for an update.  There's got to be a better way- something that notifies YOU when status changes?  That's covered in step two.

Step Two: Download URLy Warning from Download.com
Get notified instantly when a Web page changes, and see exactly what's changed. With URLy Warning, a pop-up window appears when a Web page you're watching changes, and you'll see a visual comparison of what's been added and deleted. The trial allows you to track one site in demo mode.

Once installed, you'll need to launch the app and proceed to step three.

Step Three: Configure URLy Warning
I've tried a number of tactics, but this one works best.  Click on options and set the URL to http://bensbargains.net/xbox360/xbox360.php 

Configure the rest of the settings you see below or read onfor customizations:

Setting to when at least 3 words are added or deleted will notify you when items go in or out of stock. This can result in a high count, but ensures you don't miss anything.  There are other strategies here such as setting When page contains the phrase "In Stock".

Updated Strategy: Search for changes in history only

Kevin writes, "I added a test range to only ping me on changes to the Tracker History by entering ‘History’ in the first text box and leaving the 2^nd text box blank.  This way, I only get notified when something is in stock and not when a timeout occurs."  Nice addition Kevin- thanks for the tip!  Screenie below.

You can set the app to give you a popup, a chime sound, or even send email to you or a paging device.  I used the popup and chime.  If you use the settings I did above, you'll see when words change.  If the number is in the hundreds, that means multiple deals are popping up or selling out since your last check.

Just hit reset between checks.  Plan on checking multiple times as some bundles are ridiculously priced- I played the waiting game and won.

Step Four: Get up early, check early and often
I've noticed a trend from the east coast- many stores first update their inventory between 5 and 8 am Central time.  I've seen and let go a number of high priced bundles, before getting a reasonable (MSRP) deal at Circuit City. 

Good luck and happy hunting!