You better believe that Google (Nasdaq: GOOG) wants to get closer to you. Today, Big G launched serious improvements to its YouTube video-sharing site in both big and small formats.

The updated mobile site offers a user interface that's better suited to handheld touchscreen use than ever before, shows videos using the emerging HTML5 standard instead of the usual Flash software from Adobe Systems (Nasdaq: ADBE), and now outperforms the native YouTube applications on many smartphones. Whether you're rocking a Motorola (NYSE: MOT) Droid or an Apple (Nasdaq: AAPL) iPhone, there are now many reasons to prefer the mobile Web version of YouTube over the pre-installed, special-purpose applications.

At the same time, the new YouTube Leanback interface (you must sign in) offers a revamped experience for the remote-control couch potato. Instant-on video streams, a simplified clip selection process, and big, bold buttons make Leanback a natural fit for your big-screen TV. Or rather, it will be when the Google TV product line launches this fall. Leanback is an important component of that offering, and you'll need a connected entertainment center like the planned products from Sony (NYSE: SNE) and Logitech International (Nasdaq: LOGI) to actually use it.

The site, which does run on Flash, works on computers, too (but my smartphone gets pushed over to the mobile site instead). However, you're clearly meant to enjoy this interface from the comfort of your couch, wielding a next-generation remote control.

As traditional PCs become a smaller and smaller slice of the Internet pie, Google is working hard to get onto the platforms that matter in the new wave: mobile devices and living room setups. There's still work to be done, because neither new interface is perfect. For example, I like to surf the Web from my couch with the browser provided by my Nintendo (OTC BB: NTDOY.PK) Wii, and the old YouTube XL interface works like a charm there. But both the new mobile site and Leanback fail miserably. That's one platform unsupported; there must be others.

The beauty of ushering users onto a website instead of an application, however, is that Google can make improvements on the fly without waiting for users to upgrade their apps. Whatever's wrong with these YouTube offerings today could and should be fixed in short order.

As a Google investor, I like how the company encourages users on every platform to grab a browser instead of an app, because it's a short hop from there to Google-controlled advertising. Monetization of mobile video is coming your way.