Treehouse Labs was one of a few companies at CES hosted inside the booth of a semiconductor company, because Treehouse is using that company's chips for its own products. Treehouse's main product on display was something called "BiKN" (pronounced "beacon"), which uses relatively tiny RFID tags and near-field communications to track various objects using almost any iOS device.
Because the iPhone doesn't have an RFID/NFC reader built in (yet -- someday most mobile devices may include one), you'll need an extra iPhone case that slips around the iPhone and connects to the dock connector. The other side of the system is what's called a "tag," which can be attached to your keys, a child, a pet, or anything else you want to keep track of in local space (within a few hundred feet or so). Put the tag on something, load up a tracking app on the iPhone, and you'll be able to see where the item is or ping one item with a bit of playable audio.
Treehouse will be selling the case for around US$99 sometime next month, and a set of two tags can be purchased for $49. The standard BiKN kit is pretty basic and simply helps you detect and follow tagged items on the iPhone.
Treehouse is looking to license the system to other companies, which means you may see BiKN technology pop up embedded in other gadgets -- possibly the iPhone itself. One of the demos at CES showed a plant that had a tag monitoring its own water level; a separate "gateway" enabled the plant to get more water when the tag said the water level was low. This kind of monitor circuit could be embedded in a device and the iPhone through an app, which means you could set up a pretty simple system of home automation. You could even do things like have multiple tags beep when they go out of range.
The possibilities are fascinating, and Treehouse is working on getting this kind of technology out to anyone who is interested in using or selling it. Our iPhones and iPads are quickly becoming the center of our connected worlds, even at home; Treehouse's system is one of many ways to connect even more items to that network, making it more useful for all of us.