So I think I found a pretty cool trick with Youtube on PS3 and Vita. If you've used the PS3 app, you may have seen how you can pair a phone or tablet with the PS3 and control it through that. It's pretty slick, and except for some stability issues on the PS3, it works pretty well. Since the PS3 app has come out, I've been annoyed that Sony/Google haven't taken advantage of the Vita and added support for it. It seems like a no brainer, but I've found a way around it not being supported explicitly.
The new Vita app is miles better than it was before, but even then they still didn't update it with the pairing functionality. The thing is, with the new browser update (not sure if it worked before), you can use the mobile Youtube site (which works great now) to open Youtube videos on the Vita app. Youtube links even turn into the mobile links, which you can then open in the Vita app by hitting play.
I then started tinkering with the mobile site, and in the settings, there's an option to pair it with the Youtube TV application. I tried the code the PS3 app gave me, and it paired perfectly! When you open a Youtube link on the Vita browser, it will open the mobile version of the video. You can either click play and it will open the Vita app, or in the bottom left corner, you can select to play on any paired device. When you do that, the video will begin playing on the PS3 (as long as you have the app open), and you are presented with a timeline to scrub through, a pause button, and what seem to be buttons that let you go back and forth between videos you've already watched. There is a little bit of a delay (it seemed to be more than on my phone), but it works!
So, although it's not supported in the Vita app itself, the browser is now decent enough for the mobile site to work, and all that entails, which includes the pairing stuff. Sorry for the wall of text!