These are called social bookmarking sites. They allow you to save links for future reference. You can even share your links with friends or other web users. All of these sites are free to use but do require you to register.
As a major advantage, you can access any of your saved links from any computer you happen to be using.
If you think that the info on this page can be useful for you or others, now or in future, then simply bookmark this page by clicking on one of these links and adding it to your list.
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