Belgian firm Option — a longtime player in the USB modem and embedded wireless module market — had yet to follow competitors Novatel and Sierra Wireless down the MiFi-style mobile hotspot path, but it just launched a product here at Mobile World Congress today that rethinks what exactly the term "mobile hotspot" means. The so-called Xyfi looks a lot more like a traditional USB stick than a hotspot (in fact, Option bills it as the world's smallest 3G hotspot), but it's actually both: when you plug it into your PC, it automatically prompts you to install drivers. If you do, you can use it just like you would a traditional 3G modem. If you like, though, you can ignore the driver install and simply use the USB port to power the Xyfi in hotspot mode, where it can accept up to 8 attached devices.

That alone is interesting, but the Xyfi has another trick up its sleeve — it can use either Wi-Fi or 3G for its outbound connection, and route all connected devices to use either network type in real time. In other words, it'll use Wi-Fi when you're in range of a remembered network and 3G if you're not. Your laptop, tablet, iPod touch, PS Vita, and your friend's laptop are none the wiser — they just need to be connected to the Xyfi's SSID and everything else takes care of itself. That's a big deal if you're on the road, you've got a team of laptop users (or a lot of Wi-Fi-enabled gadgets), and you want to make sure that you're always using the best network available. Option points out that carrier-branded versions of the Xyfi would have their own hotspot network (AT&T, for instance) burned into firmware out of the box, so you're automatically offloading to Wi-Fi whenever you're near, say, a Starbucks. The concept of Wi-Fi offloading is worthless unless it requires zero user intervention and it's a seamless experience, and it would seem that Option might have figured it out.

The obvious question: what about a battery? Mobile hotspots aren't very useful when they can't act as standalone devices when called upon. Option got creative here, partnering with XPAL (who has worked on Energizer and PowerSkin accessories in the past) to create a square, white brick about the size of two decks of cards that the Xyfi slots into for power without a laptop. This isn't your average MiFi battery — the XPAL unit runs 4,000mAh, and Option says it'll deliver somewhere around 8.5 hours of continuous service on HSPA+. Funnily enough, the company commented to us that AT&T wants a week out of mobile hotspots. The XPAL won't deliver that, obviously, but it's just about the best runtime you'll get out of any mobile hotspot today. (And, barring an energy storage revolution, AT&T is dreaming for the foreseeable future.)

No carrier partners have been announced for the Xyfi yet, but Option says we can expect some "in the coming weeks." The company also mentions that vertical markets — "connected cars," for instance, powered by an MVNO — will be a big market for them in 2012, so you can expect to see these sticks in places other than carrier store shelves. It seems unlikely we'll see a product like this on AT&T or Verizon until it supports LTE (the current model tops out with HSPA+), but the indication from the company is that LTE-capable devices are in the pipeline.