It's called L5 Remote, and it has two components: a free app and a not-free hardware accessory. The accessory attaches to the iPhone's USB port, then sends IR signals like most other universal remotes. It captures the signals sent out by your existing remotes so you can map them to buttons on the app. The cool part? The app lets you customize the interface by adding, deleting and moving around buttons to match your personal uses.
The app will serve as a free trial. You'll be able to download it and see all the cool things you can do, but it'll be useless without the IR hardware, which will set you back $49.95. If you already have an iPhone or iPod touch, that's probably cheaper than buying one of those dedicated touchscreen remotes.
Here's hoping that it actually works, though. The "Reviews" tab on the product's website is not working yet, and the release date is a mystery. What do you think? Is this going to be practical or just pie-in-the-sky?