When online you can watch a video while also browsing for others, and you are not limited to Youtube videos, there are really a bunch of video sites to explore. You are also able to play any video on slow motion, or fast forward.
On the video below I show how the basics of how PSPtube works. I just did a simple search. I typed in: "kof" which stands for "King of Fighters". Once the results are shown on the screen, I highlighted the one I was interested in, you can watch it without saving, but I prefer sometimes saving, and then watching it in its entirety. I pressed "O" to get the menu at right corner and then choose save, then enter once, so you can choose to rename the video, then enter again to start saving, then progress bar will fill up. Once the video is saved you can watch it on your favorites page.
There are older versions of PSPTube, but as of today this is the latest, for all PSPs with Custom Firmware (CFW)
Download this application here!(dead link) (6 MB) Mind again you need CFW to make it work, otherwise it will just come up as "corrupt data" on the screen when you try to access it. All you need to do is just put the folder named: "Ultimate PSPtube" on your "Game150" folder that is inside the PSP folder. Enjoy! Feedback is welcome! ^.^