It's taken longer than we might have thought, but cable multi-system operators (MSOs) are finally starting to add meaningful interactive functionality for subscribers.

On Tuesday, Disney (NYSE:DIS) announced an agreement with MSOs Time Warner Cable (NYSE:TWX) and Cablevision (NYSE:CVC) to let subscribers book travel arrangements with a simple click of their remotes. That announcement follows the disclosure last month that Comcast (NASDAQ:CMCSA) is buying Fandango, an Internet provider of theater tickets, which will become part of more robust interactive commerce platform at the company.

According to Disney and the two cable operators, Time Warner Cable viewers will be able to use their remote to request promotional materials relating to televised destinations discussed on a new Disney interactive video-on-demand travel channel. (Those destinations certainly include Disney's theme parks.) Cablevision viewers will be able to use their remote to request a phone call within 15 minutes from a Disney travel representative.

Both the Disney and earlier Comcast announcements signal to me that, while the technology enabling interactive commerce has long been available, MSOs are finally ready to widely deploy such features. The cable companies are nothing if not cautious about rolling out new functionalities, but with video-on-demand now significantly deployed, and the triple play of video, data, and telephony being well-received by subscribers, they seem ready to intensify their provision of interactive commerce capabilities.

It's also logical to assume that cable's movement into interactivity is being propelled by the new, steadily emerging competition from telephone companies Verizon (NYSE:VZ) and AT&T (NTSE: T), which are offering their own triple-play opportunities in a growing list of locations. In fact, I'd argue that it's only a matter of time before the cable companies will be hurt by their inability to match the phone companies' ability to include wireless in an eventual "quadruple play."

But for now, the cable companies' movement into interactivity bodes well for their subscribers. It also enhances my contention that Comcast and Time Warner Cable, in particular, represent especially attractive investment opportunities for Fools in search of solidly run companies. Both firms may also be a bit better-protected than most against any widespread economic slowdown.

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Fool contributor David Lee Smith does not own shares in any of the companies mentioned. He welcomes your questions or comments. The Motley Fool has a disclosure policy.