Though it may be a bit late for it to enter the download market, Time Warner's HBO will begin a controlled launch of HBO Broadband tomorrow, a free add-on to HBO on Demand.

The service will be made available initially to Time Warner Cable/Roadrunner high speed Internet customers in the Green Bay and Milwaukee, Wisconsin areas. There is no timeline yet for a national rollout.

HBO has said that it will add 600 new titles monthly, and an original series such as "Entourage," or "The Sopranos" will be made available in its entirety each month as well. 400 titles will reportedly be available at any time.

Content will not be available through a browser, though, as HBO Broadband relies on its own application for Windows PCs running XP and Vista. Content is downloaded directly to the subscriber's drive through the application and expires four weeks after the download date.

Each subscribing household will be allowed five user accounts and different computers to download programming. Unfortunately, portable devices are not supported yet, nor are Macs.

Since it is still early in the service's lifespan, details as to the quality of the downloads have not been made public. The limited-time nature of the downloads, however, makes HBO's business model similar to NBC Direct, a service that looks to be more of a "base covering" than genuine offering.

HBO is the US' most popular premium cable channel, with 29 million subscribers. But in terms of Web availability, it's still well behind #2 premium channel Showtime, which been offering original content on iTunes for two years.