Do you know of any online file system or repository where I can save all the URLs ?

Actually, I am into data mining, a large part of it deals with organizing data sets, I come across a number of websites, urls and yourtube links etc. which are very much useful to me. But everytime, I have to write them down in a note-book or so, it gets a bit nasty. If anyone of you could suggest me a software, app or any online system where I can save all the urls, web links, videos etc. so that I dont have to save them in a word file or write them in a note-book? Any responses shall be appreciated.