Truveo does a good job of searching for videos compatible with the iPhone
One huge positive is that it will play high quality videos over 3g ( youtube will send a lower quality video when it detects you are on 3g)
there are two negatives though
- sometimes it finds videos that will not play ( not h264 compatible)
- will not do video out like youtube
I find that sometimes Truveo will find Youtube videos that even the Youtube app will not find .
Glad to help