I've just filed an "Enhancement Request" from Apple's iPhone feedback page: http://www.apple.com/feedback/iphone.html
iPhone lacking this feature is actually leaving my "Watch Later" queue ever-growing :'(
I badly want this feature too!!
You can access them by installing the YouTube web app (visit http://m.youtube.com and add it to your home screen). Obviously it would be much better to have them in the iOS app itself but this works in the meanime.
I'm frustrated when I see the Youtube App hasn't been updated on iOS5.
No high def option? I can live with that. But no support to Watch Later?
Some of the posters above clearly doesn't get a clue how "Watch later" is working.
It is not a list that's just named "Watch later". Nor could it be replaced by favorites.
Google has done a great job implementing the list.
There's a specific button on Youtube player that add video to the list.
And that is accessible before the video even loaded, which is VERY useful.
I get that creating a new playlist isn't a direct alternative; however, using a list is one way to save a video from your computer for watching later on the iPhone.
Given that the original poster asked about Watch Later, which has never been available on the iPhone, my assumption was that he/she was saving videos to Watch Later on the Mac Book Pro listed in his/her signature. In that case, using a separate playlist works as an acceptable, if not perfect, alternative. Maybe it's different in Hong Kong, but on my YouTube.com, add to Watch Later is in the same drop-down as adding to another list.
So, while I understand your frustration, it seems to me that most of the folks above, myself included, have more clues than you give us credit for, and you might consider voicing your frustration as a suggestion to Apple.
[Edit] By the way, you're definitely right that it takes an extra click through to YouTube to add the video to playlists... If the video's embedded via iframes, the little "+ Watch Later" button saves you that step, which (I agree) would be nice to have access to. I've avoided the Watch Later function because it's not available on iPhone & the suggestions above are as good as it gets for now.
I wasn't talking about the drop-down of adding video to playlists on youtube pages.
While I may sounded hostile, I was just trying to say some don't seem to understand why the OP want the watch later list specifically.
Youtube embedded player has a button that add the video directly to watch later list.
And that button is accessible before the video itself loads.
It's very useful when u surf the web and add videos to a list to watch later (like, on the road)
And there isn't alternative that done this as easy and convenient.
edit: saw your edit, that's exactly that.
It's not exactly what you're looking for, but if you go to your playlists in YouTube in a browser and go to your Watch Now list, you can Select All and add to another list. Mine is called To-Do. Then they will be available on your iPhone/iPad when you hit the road.
Apple, please put me down for a vote for native Watch Later support in the iOS app.
Bumping the topic up...
I too would like access to the Watch Later playlist in the iOS app. The odd thing is, there was one day, just one day, that I was able to access it under Playlists in the app. But only one day. Since then it's been gone.
Why doesn't this app ever get updated? Given that built-in YouTube access is one of Apple's advertised selling points for iOS devices, and always has been, you'd think they'd want to keep this app up to date with the changes made to YouTube. Or even, gasp, let Google do the development on the YouTube app, since it's their service the app accesses? But that would make sense, so of course it'll never happen...