Check out the Timex Ironman One GPS+ smartwatch (pictures)

The rugged Timex Ironman One GPS+ might not be the prettiest smartwatch on the block, but it offers cellular data via AT&T, letting you stay in touch without toting a phone.

The watch will be available in the US and Canada later this fall for $399 -- that's fairly steep compared with competing smartwatches, but those watches lack built-in cellular connectivity.

The interface is fairly straightforward, with options to manage contacts, check your messages, listen to music, and track your workout. The four buttons surrounding the device will also help you get around.

You'll start your workout regimen on this screen. Here's also where you can configure the sensors you may have paired via Bluetooth, and fire up the GPS to track your location.

Past workouts are readily accessible, so you can get a quick idea of the sort of progress you've been making.

The 4GB of onboard storage lets you load up music so you needn't exercise in silence.

When syncing your contact info, you can also include photos that'll be displayed on the 1.5-inch Mirasol screen.

Messages you receive pop up right on the display, and you'll feel a vibration or hear an alert when someone's trying to reach you.

Messages will be a little tight on the small screen. You'll fortunately be able to respond with prerecorded messages, though you do have the option of typing things out on a virtual keyboard.

I wouldn't recommend typing things out, as hunting for and pecking at letters on the tiny display is a bit of a chore.

You can use the watch's Bluetooth connectivity to pair it with heart rate monitors, foot pod-style activity trackers, Bluetooth headsets, and your phone.

Battery life could prove problematic: with the GPS and cellular radios turned on, it's estimated at 8 hours. Play music, and that drops to 4 hours. If you're just using cellular data, however, you can expect the watch to last approximately three days.

This is not a svelte timepiece, but it feels very sturdy -- it's water-resistant to 50 meters, and should be able to take a beating.

The watch is also deceptively light: you'll certainly know you're wearing it, but it probably won't feel like a burden.