Interactive TV
Enhanced TV and Media multitasking
Internet TV and Digital TV
Enhanced TV.com
Enhanced Tv at ensequence.com
Teletext regular service
There's a bit more on the BBC's interactive TV services here. Image from here.
This one, from Malaysia, attempts to create some interesting filler in place of regular transmission.
Finally, this screenshot is of the 'in-vision' function Teletext provides/used to provide, demonstrating a somewhat dying medium. However, as the screenshots below show, the function is not fully lost, rather recontextualised, often to a more aesthetically pleasing extent:
Sources:
http://teletext.mb21.co.uk/
http://www.tkk.fi/Units/IDC/brocom/sub/terminal/abstract.html
The above movie also incorporates explanatory text alongside the typically 90s graphic styling.The below one, (mainly a musical piece) however, is more reminiscent of 80s computer graphics:
Note the animated Gif showing the advertisements switching between frames, one possible conversion of the format for the web. Pro - remains faithful to the original format, is quicker. Con - not really interactive - no hold button.