Online TV portal Joost has launched an iPhone app that lets users browse and view video on their handset where there's a Wi-Fi connection.

The free app, which is available to download from the iTunes App Store, offers music videos, comedy shows and documentaries. Users from around the world can use the app to view content, although not all of it can be accessed by those outside the US.

While the video quality was pretty impressive in our brief tests, the player was a bit glitchy: for example, we couldn't resume a 30-minute show where we left off when kicked off a Wi-Fi network, and the browsing interface is a little haphazard. Future updates are expected to add Joost's social networking features and personalisation options; hopefully, they'll bring refinements to the player mechanics as well.