Taking Videos with the iPhone
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If you taking any video with any type of smartphone it helps to hold the camera the proper way. When taking videos, you should ALWAYS hold the camera so the longest side is parallel to the ground.
The logic behind this is simple all TVs and computer monitors are in the landscape format ( also known as X in the media business) and have been that way since the 4:3 display format was adopted in 1999.
When you hold the camera the other way, you cause a display issue when you try to view it on other platforms - that includes YouTube and Vimeo. What ends up happening is you'll see black bars that are vertically align to the video. The video basically looks weird every place but on your phone.
Some television networks have created an effect to make a blur version of the video in the background so it looks a bit better. Still not an optimal way to show amateur footage.
Get in the habit of holdings the camera correctly and you'll have much better quality videos to show on YouTube and TV.
If you do take a lot of video with your iPhone, you should look into using FiLMiC Pro ($5). It's a great application that helps you take really good videos, as you have a lot more control than the standard video capture that comes with the phone. The only downside is the application does take some time to learn how to use. I use it off and on and find it to be a useful app.
If you disagree with my opinion, on how to properly hold the camera, let me know. I would be interested in hearing from my blog readers.