File these under "solutions to problems you didn't know you had."
They're the SanDisk Connect Wireless Flash Drive and Wireless Media Drive, two new gadgets that provide on-the-go solid-state storage for, and access to, movies, music, photos and documents. I've been using them for a few weeks now; they're unobtrusive, modestly priced and ridiculously useful.
Why would you want something like this? Maybe to take a few movies along on a trip without eating up the storage space on your phone or tablet. Maybe to stream a multimedia presentation to several users at once.
Or maybe it's just to keep a couple of kids in the back seat amused. With battery life of up to eight hours, the drives could make long car trips a lot quieter.
The concept of Wi-Fi-based mobile storage isn't new. Most such products, like Seagate's GoFlex Satellite, use mechanical hard drives to store your content. The SanDisk devices, by contrast, use chips.
Each approach has advantages. Hard-disk-based drives can hold much more and are cheaper on a per-gigabyte basis. The SanDisk drives are smaller, lighter, cost less out of pocket, use less power, and, since there aren't any moving parts, don't run the risk of a mechanical failure.
The Flash and Media Drives work similarly but come in different capacities and forms.
The Flash Drive looks and works like a slightly overgrown thumb drive. A tiny hatch covers a slot that houses the removable memory card.
It costs $50 for a version with a 16-gigabyte card -- enough for seven or so standard-definition movies -- and $60 for 32 GB.
The Media Drive, meanwhile, is a palm-sized square that's about 2 1/2 inches on each side and weighs 2 1/2 ounces. It costs $80 for 32 GB and $100 for 64 GB.
Both use a computer's USB port for downloading content and recharging, and can connect to up to eight mobile devices at a range of up to 150 feet. But the Media Drive has a beefier battery; the Flash Drive's maximum is four hours, and less if you're streaming to multiple devices.
The Media Drive can also recharge from a wall outlet and has a slot for an additional SD memory card, meaning you can boost its total capacity to as much as 192 GB. And it streams up to five different HD movies at one time. The Flash Drive is limited to three.
On each mobile device I wanted to use -- the drives work with Apple's iPads and iPhones, Android devices and Amazon's Kindle Fire -- I downloaded a free app. (Oddly, there are separate ones for each drive.)
To enable a device to see the content, I went into its settings and assigned the Wi-Fi connection to the SanDisk drive. This wasn't so bad, except it meant the device could no longer access the Internet.
SanDisk's solution is to enable the drive itself to access your Wi-Fi network, so your phone or tablet can go through it to reach the Net. Configuring everything is a little less annoying than it sounds, but only a little. Mercifully, you should only have to do it once.
Copying content over to a drive was a simple matter of connecting it to a PC or Mac and dragging and dropping. I moved music, photos and a PowerPoint slideshow and was able to view them on multiple devices.
Videos were a little more involved. The drives use version 2.0 of the USB standard, rather than the newer, faster 3.0, so be prepared to grab a cup of coffee if you're doing a full- length movie. In my tests, it took about five minutes to copy a standard-definition iTunes movie from an iMac to the drive and twice that for hi-def.
Once I did, I was able to watch different movies on an iPad and iPhone simultaneously -- iTunes movies run in the Safari browser -- while leafing through photos, playing music and watching shorter videos on a Kindle Fire.
All played smoothly and stutter-free from the Media Drive, and mostly from the Flash Drive as well -- except for an occasional freeze on an iPhone when three hi-def streams were going at once.
I also wirelessly copied MP3 music files from the Kindle to the drive, which I then played over the iPhone. Just remember: As with any external drive, your content has to be in a format your mobile device can play. So you can't, say, expect to watch an iTunes movie on a Google Nexus 7 tablet.
Still, with their flexibility and next-to-nothing size and weight, the Media Drive and Flash Drive make welcome companions.