I think I download the app on my samsung droid which is like a sony remote control app. if you look at the last paragraph on page one of the following link (a review that i found on google) it talks about such a thing. i have used it only once or twice and did not try any actual keyboarding because i mostly use it to mirror my ipad. http://www.soundandvisionmag.com/article/test-report-sony-bravia-xbr-55hx929-3d-lcd-hdtv
"Additionally, the models feature an improved remote control and offer control via the Media Remote application on iPhone, iPod Touch or Android mobile device. The app, which can be downloaded from the Apple App Store or the Android Marketplace, functions as a full remote with keyboard, allows online content search, and playback."
When I get a chance I will try the app and let you know if fills the bill....
There are keyboards that work with iPad tablets and Samsung Galaxy Tab (mine is an 8.9) that can input both wireless and HDMI; plus there's a USB input. However, what solution are you looking for? I don't know if the Sony accepts changes in programming code through those input sources. davzway