Here you can Download Youtube videos without any software. You'll just need to logging into http://www.tubememory.com and search what you want and click on "Download". You can download in different file formats like FLV / MP4 / 3GP.
With TubeMemory.com you can directly visit it with your mobile device and download youtube videos in 3gp file format.
Tube Memory Downloader is a powerful video script to search & download videos from YouTube and save as many different video formats, such as FLV, MP4 and 3GP. You can search, download and transfer YouTube video into your PC, iPod, PSP, iPhone, PDA, PocketPC, Cell Phone, or other portable video device.
Online MP4 YouTube Converter Downloader