Before there were "TV everywhere" apps, there was the Slingbox, a groundbreaking product that allowed you to stream your home TV signals to any PC or connected device on the planet, so long as you had the available bandwidth. After something of a hiatus -- there haven't been any new Sling products since 2008's Slingbox Pro-HD -- new Slingbox hardware was finally been released in fall 2012: the Slingbox 350 ($180) and the Slingbox 500 ($300, reviewed here).
As with past Slingbox models, the boxes digitize video streams from your cable/satellite box (or DVR) and stream them in real time to a wide variety of devices: Windows PCs and Macs, iPads, iPhones, Android phones, Android tablets (including the Kindle Fire and Kindle Fire HD), Windows phones, and even some home devices, such as the Boxee Box, Logitech Revue, and WD TV Live. There's no monthly fee, but the mobile apps cost a pricey $14.99; that's down from the previously exorbitant $29.99 price, but it's still an added cost that should be reduced to zero -- or close to it. (The streaming software on the PC and Mac is via a free browser plug-in, and the home-streaming device apps are free as well.)

Both new Slingbox models add full 1080p video streaming, upping the lesser VGA and 720p resolutions found on the now-discontinued, 2008-era
Instead I'm going to focus on the key differences between the two boxes and talk about why you might spend the extra dough on the 500 -- or not.
Built-in Wi-Fi
In addition to the built-in IR blaster and streaming features found on the Slingbox 350, the $300 Slingbox 500 adds some unique new features. Probably the most important of the bunch is built-in Wi-Fi. Yes, this the first Slingbox to offer integrated Wi-Fi -- finally! If you have a router or an Ethernet connection available near where your Slingbox is set up, this won't be a big deal. But if you don't, it's obviously a key feature that would potentially make the 500 worth buying over the 350. Naturally you'll need a wireless network to tap into, but in my tests at home, setup was simple: you simply scan for your network, then type in its password (if it has one) using an onscreen virtual keyboard that you navigate with the included remote.
HDMI support
The 500 is also the first Slingbox to offer HDMI support (again: finally!), albeit with the usual caveat: if the broadcaster uses the most aggressive digital "flag," that channel or program won't be streamable via HDMI. For that reason, Sling recommends still connecting the component video input as well -- a "belt and suspenders" approach, a company rep told us.
Discuss Slingbox 500