How to download songs from Youtube to my iPhone?

I've been using shareyoutubemp3.com but its not working on my computer anymore. Is the website down or something? Anyways, Can someone help me find a new website that's easy to download songs off of Youtube onto my iPhone, please? Thanks!

Added (1). Oh and I don't want anything that you have to sign up and create an account, and it would be great if it would be really quick and simple.

Not a website but it's free software: http://www.dvdvideosoft.com/products/dvd/Free-YouTube-to-iPhone-Converter.htm

I think the website is blocked by Chrome. Therefore, you need to download YouTube videos as MP3 files with other methods. Follow those steps below to do it for free:
1. Download YouTube video with Keepvid, a free website for YouTube downloading and converting.
2. Convert the downloaded video to MP3 files with Moyea Video4Web Converter, a powerful video to audio tool.

You may try videotomp3, it can help you convert youtube video to mp3 song, and then you can use iTunes to sync the mp3 songs to your iPhone.