The one drawback is that the viewer currently only works only with Wi-Fi, which is contrary to their claim that your can watch Ustream anywhere "regardless of where you are at and what you are doing, you can choose to be in the moment with others in a shared live experience around a live event. If you are out-on-the-town and know that a guest speaker at a major conference is “going live” and want to watch live and be-in-the-crowd."
According to John Ham, Ustream Founder, "The Ustream iPhone Viewing Application was pending approval from Apple and was approved in time for the inauguration. Now any iPhone owner can watch the inauguration from their iPhone. Presently, the Ustream iPhone Viewing Application is WiFi only to ensure the highest quality broadcast on the iPhone, but stay tuned for developments."
They may have scaled back the application to Wi-fi only to comply with ATT's terms of service and keep the live video traffic off of the ATT 3G network. But doesn't anywhere mean anywhere? Even the graphic I used in this post from the Ustream blog says "anywhere" and not "anywhere there is Wi-fi." So technically this application allows you to view live and on-demand Ustream content similar to Joost's iPhone app.
I haven't tested the Ustream app myself, but I've read several reviews which have been favorable. Here's a few posts from people who have tested the app:
- Just in time for the Obama inauguration, Ustream’s iPhone app launches » VentureBeat
- Ustream iPhone app makes App Store in time for inaugural address | Feeds | ZDNet.com
- Ustream’s Live Viewing App Hits the App Store » Apple Universe Podcast
- Ustream viewer makes it to app store just in time - The Unofficial Apple Weblog (TUAW)
Gallery: Ustream Screen shots