how do i create a playlist in itunes from my iphone 4s?

You can create a playlist directly on your iPhone, by going to the playlist tab in the music app, and then syncing with iTunes.

While that is true for auto-sync, a playlist that you create on your iPhone won't transfer to your iTunes library if you manually manage music on the iPhone.

Yes I know, the OP didn't mention manual management.

Go into the playlist tab, you will see a + in the top right. Then navigate to the 2 songs and select them. Hit DONE

denisefromnj wrote:

On my iphone 4s I have 2 songs in the purchased category that I want to manually move into an existing playlist. I can not figure it out.

If the existing playlist is a regular (non-smart) playlist, then you can edit it directly on the iPhone. Just select the playlist and you should see an "Edit" button at the top, above the songs. If you don't see that, then it must be a smart playlist since those can't be edited on the device. Once you tap the Edit button you would then navigate to the song you want to add and press the blue + sign to the right of the song, then press Done when you're finished.

One caveat though, if you auto-sync your iPhone, the changes you make will not be preserved -- the playlist will revert to how it was next time you sync to iTunes. So if you want to edit a playlist on your iPhone and then transfer it to iTunes, you have to create a new (empty) playlist on your iPhone, add the playlist that you wanted to edit to the new playlist, then add or delete more songs to the new playlist. When you auto-sync, the new playlist will transfer to your iTunes library.

But if you manually manage your iPhone, the playlist should remain in its edited state even if you connect to your library (but admittedly its been awhile since I tried manual mode).